Control of polymer architecture and molecular weight distribution via multi-centered shuttling agent

ABSTRACT

A process for the polymerization of one or more addition polymerizable monomers and the resulting polymer composition, said process comprising contacting an addition polymerizable monomer or mixture of monomers in a reactor or reactor zone with a composition comprising at least one polymerization catalyst and a cocatalyst under polymerization conditions, characterized in that at least a portion of said polymerization is conducted in the presence of a multi-centered shuttling agent thereby causing the composition to have a bimodal molecular weight distribution.

CROSS REFERENCE STATEMENT

This application claims the benefit of U.S. Provisional Application No.60/717,543, filed Sep. 15, 2005.

BACKGROUND OF THE INVENTION

The present invention relates to a process for polymerizing a monomer ormixtures of two or more monomers such as mixtures of ethylene and one ormore comonomers, to form an interpolymer product having unique physicalproperties, to a process for preparing such interpolymers, and to theresulting polymer products. In another aspect, the invention relates tothe articles prepared from these polymers. The inventive polymerproducts include blends of generally uniform chemical composition andrelatively broad molecular weight distribution, including a blend of twoor more polymers of uniform monomer composition but differing in that atleast one component has substantially higher in molecular weight than atleast one other component. Also included are mixtures of two or morepolymers comprising regions or segments (blocks) of differing chemicalcomposition, characterized by the foregoing molecular weightdistribution characteristics. In addition, at least one of theconstituents of the polymer mixture contains a linking group which isthe remnant of a multi-centered shuttling agent, causing the polymer topossess unique physical properties. These polymeric products and blendscomprising the same are usefully employed in the preparation of solidarticles such as moldings, films, sheets, and foamed objects by molding,extruding, or other processes, and are useful as components oringredients in adhesives, laminates, polymeric blends, and other enduses. The resulting products are used in the manufacture of componentsfor automobiles, such as profiles, bumpers and trim parts; packagingmaterials; electric cable insulation, and other applications.

The use of certain metal alkyl compounds and other compounds, such ashydrogen, as chain transfer agents to interrupt chain growth in olefinpolymerizations is well known in the art. In addition, it is known toemploy such compounds, especially aluminum alkyl compounds, asscavengers or as cocatalysts in olefin polymerizations. InMacromolecules, 33, 9192-9199 (2000) the use of certain aluminumtrialkyl compounds as chain transfer agents in combination with certainpaired zirconocene catalyst compositions resulted in polypropylenemixtures containing small quantities of polymer fractions containingboth isotactic and atactic chain segments. In Liu and Rytter,Macromolecular Rapid Comm., 22, 952-956 (2001) and Bruaseth and Rytter,Macromolecules, 36, 3026-3034 (2003) mixtures of ethylene and 1-hexenewere polymerized by a similar catalyst composition containingtrimethylaluminum chain transfer agent. In the latter reference, theauthors summarized the prior art studies in the following manner (somecitations omitted):

-   -   “Mixing of two metallocenes with known polymerization behavior        can be used to control polymer microstructure. Several studies        have been performed of ethene polymerization by mixing two        metallocenes. Common observations were that, by combining        catalysts which separately give polyethene with different Mw,        polyethene with broader and in some cases bimodal MWD can be        obtained. [S]oares and Kim (J. Polym. Sci., Part A: Polym.        Chem., 38, 1408-1432 (2000)) developed a criterion in order to        test the MWD bimodality of polymers made by dual single-site        catalysts, as exemplified by ethene/1-hexene copolymerization of        the mixtures Et(hid)₂ZrCl₂/Cp₂HfCl₂ and Et(Ind)₂ZrCl₂/CGC        (constrained geometry catalyst) supported on silica. Heiland and        Kaminsky (Makromol. Chem., 193, 601-610 (1992)) studied a        mixture of Et-(Ind)₂ZrCl₂ and the hafnium analogue in        copolymerization of ethene and 1-butene.    -   These studies do not contain any indication of interaction        between the two different sites, for example, by readsorption of        a terminated chain at the alternative site. Such reports have        been issued, however, for polymerization of propene. Chien et        al. (J. Polym. Sci. Part A: Polym. Chem., 37, 2439-2445 (1999),        Makromol., 30, 3447-3458 (1997)) studied propene polymerization        by homogeneous binary zirconocene catalysts.

A blend of isotactic polypropylene (i-PP), atactic polypropylene (a-PP),and a stereoblock fraction (i-PP-b-a-PP) was obtained with a binarysystem comprising an isospecific and an aspecific precursor with aborate and TIBA as cocatalyst. By using a binary mixture of isospecificand syndiospecific zirconocenes, a blend of isotactic polypropylene(i-PP), syndiotactic polypropylene (s-PP), and a stereoblock fraction(i-PP-b-s-PP) was obtained. The mechanism for formation of thestereoblock fraction was proposed to involve the exchange of propagatingchains between the two different catalytic sites. Przybyla and Fink(Acta Polym., 50, 77-83 (1999)) used two different types of metallocenes(isospecific and syndiospecific) supported on the same silica forpropene polymerization. They reported that, with a certain type ofsilica support, chain transfer between the active species in thecatalyst system occurred, and stereoblock PP was obtained. Lieber andBrintzinger (Macromol. 3, 9192-9199 (2000)) have proposed a moredetailed explanation of how the transfer of a growing polymer chain fromone type of metallocene to another occurs. They studied propenepolymerization by catalyst mixtures of two different ansa-zirconocenes.The different catalysts were first studied individually with regard totheir tendency toward alkyl-polymeryl exchange with the alkylaluminumactivator and then pairwise with respect to their capability to producepolymers with a stereoblock structure. They reported that formation ofstereoblock polymers by a mixture of zirconocene catalysts withdifferent stereoselectivities is contingent upon an efficient polymerylexchange between the Zr catalyst centers and the A1 centers of thecocatalyst.”

Brusath and Rytter then disclosed their own observations using pairedzirconocene catalysts to polymerize mixtures of ethylene/1-hexene andreported the effects of the influence of the dual site catalyst onpolymerization activity, incorporation of comonomer, and polymermicrostructure using methylalumoxane cocatalyst.

Analysis of the foregoing results indicate that Rytter and coworkerslikely failed to utilize combinations of catalyst, cocatalyst, and thirdcomponents that were capable of readsorption of the polymer chain fromthe chain transfer agent onto both of the active catalytic sites, thatis they failed to obtain two-way readsorption. While indicating thatchain termination due to the presence of trimethylaluminum likelyoccurred with respect to polymer formed from the catalyst incorporatingminimal comonomer, and thereafter that polymeryl exchange with the moreopen catalytic site followed by continued polymerization likelyoccurred, evidence of the reverse flow of polymer ligands appeared to belacking in the reference. In fact, in a later communication, Rytter, et.al., Polymer, 45, 7853-7861 (2004), it was reported that no chaintransfer between the catalyst sites actually took place in the earlierexperiments. Similar polymerizations were reported in WO98/34970.

In U.S. Pat. Nos. 6,380,341 and 6,169,151, use of a “fluxional”metallocene catalyst, that is a metallocene capable of relatively facileconversion between two stereoisomeric forms having differingpolymerization characteristics such as differing reactivity ratios wassaid to result in production of olefin copolymers having a “blocky”structure. Disadvantageously, the respective stereoisomers of suchmetallocenes generally fail to possess significant difference in polymerformation properties and are incapable of forming both highlycrystalline and amorphous block copolymer segments, for example, from agiven monomer mixture under fixed reaction conditions. Moreover, becausethe relative ratio of the two “fluxional” forms of the catalyst cannotbe varied, there is no ability, using “fluxional” catalysts, to varypolymer block composition or to vary the ratio of the respective blocks.

In JACS, 2004, 126, 10701-10712, Gibson, et al discuss the effects of“catalyzed living polymerization” on molecular weight distribution. Theauthors define catalyzed living polymerization in this manner:

“ . . . if chain transfer to aluminum constitutes the sole transfermechanism and the exchange of the growing polymer chain between thetransition metal and the aluminum centers is very fast and reversible,the polymer chains will appear to be growing on the aluminum centers.This can then reasonably be described as a catalyzed chain growthreaction on aluminum . . . . An attractive manifestation of this type ofchain growth reaction is a Poisson distribution of product molecularweights, as opposed to the Schulz-Flory distribution that arises whenβ-H transfer accompanies propagation.”

The authors reported the results for the catalyzed livinghomopolymerization of ethylene using an iron containing catalyst incombination with ZnEt₂, ZnMe₂, or Zn(i-Pr)₂. Homoleptic alkyls ofaluminum, boron, tin, lithium, magnesium and lead did not inducecatalyzed chain growth. Using GaMe₃ as cocatalyst resulted in productionof a polymer having a narrow molecular weight distribution. However,after analysis of time-dependent product distribution, the authorsconcluded this reaction was, “not a simple catalyzed chain growthreaction.” Similar processes employing similar catalysts have beendescribed in U.S. Pat. Nos. 5,210,338, 5,276,220, and 6,444,867.

It is known in the art that the presence of long chain branching (LCB)may improve certain polymer characteristics, especially processabilityand melt strength. The presence of LCB in a polymer is characterized bythe occurrence of polymer moieties of a length greater than that of anyC₃₋₈ olefin comonomer remnant attached to the main, backbone polymerchain. In prior art techniques, long chain branching may be generated ina polymer by incorporation of a vinyl-terminated macromer (eitherdeliberately added or formed in situ during a polymerization such asthrough β-hydride elimination) either by action of the polymerizationcatalyst itself or by the use of a linking agent. These methodsgenerally suffer from incomplete incorporation of the vinyl-terminatedmacromer or linking moiety into the polymer, and/or a lack of controlover the extent of LCB for given process conditions.

There remains a need in the art for a polymerization process that iscapable of preparing copolymers having unique properties in a high yieldprocess adapted for commercial utilization. Moreover, it would bedesirable if there were provided an improved process for preparingpolymers, including copolymers of two or more comonomers such asethylene and one or more comonomers, by the use of a multi-centeredshuttling agent (MSA) to introduce coupled or branched properties,including long chain branching, in the resulting pseudo-blockcopolymers, in a controlled manner. More specifically, it would bedesirable to provide a method for generating long chain branching inolefin polymers that does not require incorporation of a polymerizablefunctional group, such as a vinyl group into the polymer chain. Inaddition it would be desirable to provide such an improved process forpreparing the foregoing coupled or branched pseudo-block copolymerproducts in a continuous process.

SUMMARY OF THE INVENTION

According to the present invention there is now provided an olefinpolymer composition uniquely characterized by a broad, especially amultimodal molecular weight distribution and a process for thepreparation thereof. In particular, the present composition comprisestwo or more olefin polymers differing in molecular weights, wherein theweight average molecular weights of at least two such polymers differ byapproximately an integer multiple. The polymer mixture is prepared insitu by the polymerization of one or more addition polymerizablemonomers, preferably of two or more addition polymerizable monomers,especially ethylene and at least one copolymerizable comonomer,propylene and at least one copolymerizable comonomer having 4 or morecarbons, or 4-methyl-1-pentene and at least one differentcopolymerizable comonomer having 4 or more carbons, optionallycomprising multiple blocks or segments of differentiated polymercomposition or properties, especially blocks or segments comprisingdiffering comonomer incorporation levels. The process comprisescontacting an addition polymerizable monomer or mixture of monomersunder addition polymerization conditions with a composition comprisingat least one addition polymerization catalyst, a cocatalyst and amulti-centered shuttling agent.

Because the polymer is comprised of at least some polymer joined bymeans of one or more remnants of a multi-centered shuttling agent, theresulting polymeric composition possesses unique physical and chemicalproperties compared to random mixtures of polymers of the same grosschemical composition and compared to pseudo-block copolymers preparedwith a chain shuttling agent lacking in multiple shuttling centers.Depending on the number of active centers in the multi-centeredshuttling agent, that is, whether each shuttling agent molecule has two,three or more active shuttling sites, and the number of separateadditions of such agent, the resulting polymer may be distinctlymulti-modal or form a more uniform, broad distribution of molecularweight polymers and/or branched or multiply branched. In general, theresulting polymers contain reduced incidence of crosslinked polymerformation evidenced by reduced gel fraction. Preferably, the polymers ofthe invention comprise less than 2 percent of a crosslinked gelfraction, more preferably less than 1 percent crosslinked gel fraction,and most preferably less than 0.5 percent of crosslinked gel fraction.

In another embodiment of the invention there is provided a copolymer,especially such a copolymer comprising in polymerized form ethylene anda copolymerizable comonomer, propylene and at least one copolymerizablecomonomer having from 4 to 20 carbons, or 4-methyl-1-pentene and atleast one different copolymerizable comonomer having from 4 to 20carbons, said copolymer comprising two or more, preferably two or threeintramolecular regions comprising differing chemical or physicalproperties, especially regions of differentiated comonomerincorporation, joined in a dimeric, linear, branched or polybranchedpolymer structure. Such polymers may be prepared by altering thepolymerization conditions during a polymerization that includes amulti-centered shuttling agent, for example by using two reactors withdiffering comonomer ratios, multiple catalysts with differing comonomerincorporation abilities, or a combination of such process conditions,and optionally a polyfunctional coupling agent.

In another embodiment of the invention there is provided a process andthe resulting polymer, said process comprising:

polymerizing one or more olefin monomers in the presence of an olefinpolymerization catalyst and a multi-centered shuttling agent (MSA) in apolymerization reactor or zone thereby causing the formation of at leastsome quantity of a polymer joined with the remnant of the multi-centeredshuttling agent.

In yet another embodiment of the invention there is provided a processand the resulting polymer, said process comprising:

polymerizing one or more olefin monomers in the presence of an olefinpolymerization catalyst and a multi-centered shuttling agent (MSA) in apolymerization reactor or zone thereby causing the formation of at leastsome quantity of an initial polymer joined with the remnant of themulti-centered shuttling agent within the reactor or zone;

discharging the reaction product from the first reactor or zone to asecond polymerization reactor or zone operating under polymerizationconditions that are distinguishable from those of the firstpolymerization reactor or zone;

transferring at least some of the initial polymer joined with theremnant of the multi-centered shuttling agent to an active catalyst sitein the second polymerization reactor or zone by means of at least oneremaining shuttling site of the multi-centered shuttling agent; and

conducting polymerization in the second polymerization reactor or zoneso as to form a second polymer segment bonded to some or all of theinitial polymer by means of a remnant of the multi-centered shuttlingagent, said second polymer segment having distinguishable polymerproperties from the initial polymer segment.

Highly desirably, the polymer products herein comprise at least somequantity of a polymer containing two or more blocks or segments joinedby means of a remnant of a multi-centered shuttling agent. Generally theproduct comprises distinct polymer species having different molecularweights, ideally the larger molecular weights being integer multiples ofthe smallest. As a general rule, the product comprises a first polymerhaving a first molecular weight and at least some quantity of a secondpolymer having a molecular weight that is approximately an integermultiple of the molecular weight of the first polymer, wherein theinteger is equal to the number of shuttling centers in the shuttlingagent. The polymer recovered from the present process may be terminatedto form conventional type polymers, coupled through use of apolyfunctional coupling agent to form multiblock copolymers, includinghyper-branched or dendrimeric copolymers, or functionalized byconversion of remnants of the multi-centered shuttling agents intovinyl-, hydroxyl-, amine-, silane, carboxylic acid-, carboxylic acidester, ioniomeric, or other functional groups, according to knowntechniques.

In one embodiment of the invention a two-centered shuttling agent isused, resulting in polymers containing at least some quantity of apolymer containing the remnant of the two-centered chain shuttling agentand further step growth polymers based thereon. The resulting product isa polydisperse, in situ prepared, polymer blend, typically having abimodal molecular weight distribution with one peak approximately twicethe molecular weight of the other. If both a multi-centered shuttlingagent and a monocenter chain shuttling agent are employed, eithersimultaneously or sequentially in the same polymerization, the result isa mixture of polymer products having polydisperse molecular weightdistribution and pseudo-block copolymer properties.

In yet another embodiment of the invention, the multi-centered shuttlingagent employed in the foregoing processes is a two-centered shuttlingagent, which uniquely causes the formation of a product comprisingdistinct polymer segments after undergoing sequential polymerization intwo reactors or zones connected in series. In a further preferredembodiment, the two-centered shuttling agent's active sites are locatednear or at both termini of a linear shuttling agent (or form such ashuttling agent by ring opening of a cyclic MSA) and result in theformation of terminally functionalized polymers, including thosepolymers converted into further functional groups as previouslydisclosed. The foregoing two-centered shuttling agents are referred tohere-in-after as α,ω-two-centered shuttling agents due to theirusefulness in the formation of α,ω-di-functionalized polymers,particularly low molecular weight α,ω-dihydroxy- orα,ω-divinyl-substituted polyolefins having a molecular weights from 500to 10,000, preferably from 1000 to 6000. Such products may be preparedby the reaction of oxygen or an oxygen-containing electrophile with thealpha-omega di-metallated polymer formed by incorporation of the presentα,ω-two-centered shuttling agent into a growing polymer, or bydisplacement of the metal center with an olefin, such as ethylene, tomake the α,ω-diene, which may then be converted to the diol byhydroformylation and hydrogenation if desired. Such polymers, especiallylow molecular weight versions thereof are useful for conversion topolyurethanes, polyesters, and other products used in coating, adhesive,sealant and elastomer production.

In the foregoing embodiments of the invention, the resulting polymer maybe linear or contain one or more branching centers, depending on whethera two-centered-, three-centered-, or higher centered shuttling agent isemployed. Highly desirably, the foregoing copolymers are characterizedby terminal blocks or segments of polymer having higher tacticity orcrystallinity from at least some remaining blocks or segments. Even morepreferably, the polymer is a triblock copolymer comprising a centralpolymer block or segment that is relatively amorphous or evenelastomeric.

In yet another embodiment, the MSA is a three centered shuttling agentand the resulting polymers are characterized by the presence of longchain branching. In this embodiment, there is furthermore provided amethod for generating long chain branching in olefin polymers withoutuse of a polymerizable functional group, such as a vinyl group. Instead,the LCB branch point is the remnant of such a three-centered MSA.Because the extent of LCB in the polymer is easily controlled byaddition of the three centered MSA to a polymerization reaction at thedesired rate the resulting process is advantaged over prior artprocesses.

In a still further embodiment of the present invention, there isprovided a polymer mixture comprising: (1) an organic or inorganicpolymer, preferably a homopolymer of ethylene or of propylene and/or acopolymer of ethylene or propylene with one or more copolymerizablecomonomers, and (2) a polymer or polymer mixture according to thepresent invention or prepared according to the process of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of one process for forming apolymer composition according to the present invention using a singlecatalyst.

FIG. 2 is a schematic representation of an alternate process for forminga polymer composition according to the present invention using a singlecatalyst.

FIG. 3 is a schematic representation of one process for forming amulti-modal polymer composition according to the present invention usingtwo different catalysts.

FIG. 4 is a schematic representation of one process for forming adiblock copolymer composition according to the present invention usingtwo different catalysts.

DETAILED DESCRIPTION OF THE INVENTION

All references to the Periodic Table of the Elements herein shall referto the Periodic Table of the Elements, published and copyrighted by CRCPress, Inc., 2003. Also, any references to a Group or Groups shall be tothe Group or Groups reflected in this Periodic Table of the Elementsusing the IUPAC system for numbering groups. Unless stated to thecontrary, implicit from the context, or customary in the art, all partsand percents are based on weight. For purposes of United States patentpractice, the contents of any patent, patent application, or publicationreferenced herein are hereby incorporated by reference in their entirety(or the equivalent US version thereof is so incorporated by reference)especially with respect to the disclosure of synthetic techniques,definitions (to the extent not inconsistent with any definitionsprovided herein) and general knowledge in the art.

The term “comprising” and derivatives thereof is not intended to excludethe presence of any additional portion, component, step or procedure,whether or not the same is disclosed herein. In order to avoid anydoubt, all compositions claimed herein through use of the term“comprising” may include any additional additive, adjuvant, or compoundwhether polymeric or otherwise, unless stated to the contrary. Incontrast, the term, “consisting essentially of” excludes from the scopeof any succeeding recitation any other portion, component, step orprocedure, excepting those that are not essential to operability. Theterm “consisting of” excludes any portion, component, step or procedurenot specifically delineated or listed. The term “or”, unless statedotherwise, refers to the listed members individually as well as in anycombination.

The term “polymer”, includes both homopolymers, that is, homogeneouspolymers prepared from a single monomer, and copolymers (interchangeablyreferred to herein as interpolymers), meaning polymers prepared byreaction of at least two monomers or otherwise containing chemicallydifferentiated segments or blocks therein even if formed from a singlemonomer. More specifically, the term “polyethylene” includeshomopolymers of ethylene and copolymers of ethylene and one or more C₃₋₈α-olefins. The term “crystalline” if employed, refers to a polymer thatpossesses a first order transition or crystalline melting point (Tm) asdetermined by differential scanning calorimetry (DSC) or equivalenttechnique. The term may be used interchangeably with the term“semicrystalline”. The term “amorphous” refers to a polymer lacking acrystalline melting point. The term “elastomer” or “elastomeric” refersto a polymer or polymer segment having Tg less than 0° C., morepreferably less than −15° C., most preferably less than −25° C., and asample of which, when deformed by application of stress, is generallycapable of recovering its size and shape when the deforming force isremoved. Specifically, as used herein, elastic or elastomeric is meantto be that property of any material which upon application of a biasingforce, permits that material to be stretchable to a length which is atleast 25 percent greater than its unbiased length without rupture, andthat will cause the material to recover at least 40 percent of itselongation upon release of the force. A hypothetical example which wouldsatisfy this definition of an elastomeric material would be a 1 cmsample of a material which may be elongated to a length of at least 1.25cm and which, upon being elongated to 1.25 cm and released, will recoverto a length of not more than 1.15 cm. Many elastic materials may bestretched by much more than 25 percent of their relaxed length, and manyof these will recover to substantially their original relaxed lengthupon release of the elongating force.

The term “pseudo-block copolymer” refers to a copolymer comprising twoor more blocks or segments of differing chemical or physical properties,such as variable comonomer content, crystallinity, density, tacticity,regio-error, or other property. Non-adjacent blocks are not necessarilyof identical chemical composition, but may vary in one or more of theforegoing respects, from the composition of all other blocks or regions.Compared to random copolymers, pseudo-block copolymers possesssufficient differences in chemical properties, especially crystallinity,between blocks or segments, and sufficient block lengths to achieve oneor more of the desired properties of true block copolymers, such asthermoplastic/elastomeric properties, while at the same time beingamenable to preparation in conventional olefin polymerization processes,especially continuous solution polymerization processes employingcatalytic quantities of polymerization catalysts. The polymers andblocks thereof fit a broader distribution than conventional blockcopolymers, which in theory have molecular weight distributions of 1.0.Pseudo-block copolymers possess broader molecular weight distributions.In addition, the respective blocks of a pseudo-block copolymer desirablypossess a PDI fitting a Schulz-Flory distribution rather than a Poissondistribution.

It may be readily appreciated by the skilled artisan that in oneembodiment of the present invented process the MSA may be added once,more than once (intermittently) or added continuously to eachpolymerization reactor or zone employed in the polymerization. Highlydesirably, the MSA is added to the reaction mixture prior to initiationof polymerization, at the same time as polymerization is initiated, orat least during a significant portion of the time in whichpolymerization is conducted, especially in the first reactor if multiplereactors are utilized. Thorough mixing of MSA and reaction mixture maybe occasioned by active or static mixing devices or by use of anystirring or pumping device employed in mixing or transferring thereaction mixture.

As used herein with respect to a chemical compound, unless specificallyindicated otherwise, the singular includes all isomeric forms and viceversa (for example, “hexane”, includes all isomers of hexaneindividually or collectively). The terms “compound” and “complex” areused interchangeably herein to refer to organic-, inorganic- andorganometal compounds. The term, “atom” refers to the smallestconstituent of an element regardless of ionic state, that is, whether ornot the same bears a charge or partial charge or is bonded to anotheratom. The term “heteroatom” refers to an atom other than carbon orhydrogen. Preferred heteroatoms include: F, Cl, Br, N, O, P, B, S, Si,Sb, Al, Sn, As, Se and Ge.

The term, “hydrocarbyl” refers to univalent substituents containing onlyhydrogen and carbon atoms, including branched or unbranched, saturatedor unsaturated, cyclic or noncyclic species. Examples include alkyl-,cycloalkyl-, alkenyl-, alkadienyl-, cycloalkenyl-, cycloalkadienyl-,aryl-, and alkynyl- groups. “Substituted hydrocarbyl” refers to ahydrocarbyl group that is substituted with one or more nonhydrocarbylsubstituent groups. The terms, “heteroatom containing hydrocarbyl” or“heterohydrocarbyl” refer to univalent groups in which at least one atomother than hydrogen or carbon is present along with one or more carbonatom and one or more hydrogen atoms. The term “heterocarbyl” refers togroups containing one or more carbon atoms and one or more heteroatomsand no hydrogen atoms. The bond between the carbon atom and anyheteroatom as well as the bonds between any two heteroatoms, may besaturated or unsaturated. Thus, an alkyl group substituted with aheterocycloalkyl-, substituted heterocycloalkyl-, heteroaryl-,substituted heteroaryl-, alkoxy-, aryloxy-, dihydrocarbylboryl-,dihydrocarbylphosphino-, dihydrocarbylamino-, trihydrocarbylsilyl-,hydrocarbylthio-, or hydrocarbylseleno- group is within the scope of theterm heteroalkyl. Examples of suitable heteroalkyl groups includecyano-, benzoyl-, (2-pyridyl)methyl-, and trifluoromethyl- groups.

As used herein the term “aromatic” refers to a polyatomic, cyclic,conjugated ring system containing (4δ+2) π-electrons, wherein δ is aninteger greater than or equal to 1. The term “fused” as used herein withrespect to a ring system containing two or more polyatomic, cyclic ringsmeans that with respect to at least two rings thereof, at least one pairof adjacent atoms is included in both rings. The term “aryl” refers to amonovalent aromatic substituent which may be a single aromatic ring ormultiple aromatic rings which are fused together, linked covalently, orlinked to a common group such as a methylene or ethylene moiety. Thearomatic ring(s) may include phenyl, naphthyl, anthracenyl, andbiphenyl, among others.

“Substituted aryl” refers to an aryl group in which one or more hydrogenatoms bound to any carbon is replaced by one or more functional groupssuch as alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl,heterocycloalkyl, substituted heterocycloalkyl, halogen, alkylhalos(e.g., CF₃), hydroxy, amino, phosphido, alkoxy, amino, thio, nitro, andboth saturated and unsaturated cyclic hydrocarbons which are fused tothe aromatic ring(s), linked covalently or linked to a common group suchas a methylene or ethylene moiety. The common linking group may also bea carbonyl as in benzophenone or oxygen as in diphenylether or nitrogenin diphenylamine.

The term, “comonomer incorporation index”, refers to the percentcomonomer incorporated into a copolymer prepared by the catalyst underconsideration. The selection of metal complexes or catalyst compositionshaving the greatest difference in comonomer incorporation indices underdifferent polymerization conditions, in one embodiment of the presentinvention, results in copolymers from two or more monomers having thelargest difference in block or segment properties, such as density, forthe same comonomer composition distribution. Comonomer incorporationindex is generally determined by the use of NMR spectroscopictechniques. It may also be estimated based on monomer reactivities andreactor kinetics according to known theoretical techniques.

In a polymer containing distinguishable segments each segment may be thesame or chemically different or generally characterized by adistribution of properties. The latter result may be achieved if thepolymer chain experiences different polymerization conditions indiffering reactors or polymerization zones during formation. Differentpolymerization conditions in the respective reactors or zones includethe use of different monomers, different comonomers, or differentmonomer/comonomer(s) ratios, different polymerization temperatures,pressures or partial pressures of various monomers, different catalysts,simultaneous use of mono-centered chain shuttling agents, differingmonomer gradients, or any other difference leading to formation of adistinguishable polymer segment. In this manner, at least a portion ofthe polymer resulting from the present process may comprise two, three,or more, preferably two or three, differentiated polymer segment typesarranged intramolecularly.

According to the present invention, by selecting highly active catalystcompositions capable of rapid transfer of polymer segments both to andfrom a suitable multi-centered shuttling agent, a polymer product havingat least two different molecular weight fractions is formed. Due to theuse of at least one multi-centered shuttling agent and catalysts capableof rapid and efficient exchange of growing polymer chains, the polymerexperiences discontinuous polymer growth and transfer to a remnant ofthe multi-centered shuttling agent, thereby forming at least somepolymer having approximately double, triple or other multiple of themolecular weight of a remaining component of the polymer blend, andoptionally, chemically distinct polymer segments.

By the term, “approximately” as used with respect to the comparison ofmodes in a multi-modal molecular weight distribution of a polymer blendherein, is meant that the mean molecular weight of the higher molecularweight component of the multi-modal blend is within 15 percent,preferably within 10 percent of an integer multiple of the lowermolecular weight component, said integer being 2 or higher.

Monomers

Suitable monomers for use in preparing the copolymers of the presentinvention include any addition polymerizable monomer, preferably anyolefin or diolefin monomer, more preferably any α-olefin, and mostpreferably ethylene and at least one copolymerizable comonomer,propylene and at least one copolymerizable comonomer having from 4 to 20carbons, or 4-methyl-1-pentene and at least one differentcopolymerizable comonomer having from 4 to 20 carbons. Examples ofsuitable monomers include straight-chain or branched α-olefins of 2 to30, preferably 2 to 20 carbon atoms, such as ethylene, propylene,1-butene, 1-pentene, 3-methyl-1-butene, 1-hexane, 4-methyl-1-pentene,3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene and 1-eicosene; cycloolefins of 3 to 30,preferably 3 to 20 carbon atoms, such as cyclopentene, cycloheptene,norbornene, 5-methyl-2-norbornene, tetracyclododecene, and2-methyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene; di-and poly-olefins, such as butadiene, isoprene, 4-methyl-1,3-pentadiene,1,3-pentadiene, 1,4-pentadiene, 1,5-hexadiene, 1,4-hexadiene,1,3-hexadiene, 1,3-octadiene, 1,4-octadiene, 1,5-octadiene,1,6-octadiene, 1,7-octadiene, ethylidene norbornene, vinyl norbornene,dicyclopentadiene, 7-methyl-1,6-octadiene,4-ethylidene-8-methyl-1,7-nonadiene, and 5,9-dimethyl-1,4,8-decatriene;aromatic vinyl compounds such as mono- or poly-alkylstyrenes (includingstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene,o,p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene and p-ethylstyrene),and functional group-containing derivatives, such as methoxystyrene,ethoxystyrene, vinylbenzoic acid, methyl vinylbenzoate, vinylbenzylacetate, hydroxystyrene, o-chlorostyrene, p-chlorostyrene,divinylbenzene, 3-phenylpropene, 4-phenylpropene and α-methylstyrene,vinylchloride, 1,2-difluoroethylene, 1,2-dichloroethylene,tetrafluoroethylene, and 3,3,3-trifluoro-1-propene, provided the monomeris polymerizable under the conditions employed.

Preferred monomers or mixtures of monomers for use in combination withat least one MSA herein include ethylene; propylene; mixtures ofethylene with one or more monomers selected from the group consisting ofpropylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, andstyrene; and mixtures of ethylene, propylene and a conjugated ornon-conjugated diene.

Chain Shuttling Agents

The term, “shuttling agent” or “chain shuttling agent”, refers to acompound or mixture of compounds that is capable of causing polymeryltransfer between the various active catalyst sites under the conditionsof the polymerization. That is, transfer of a polymer fragment occursboth to and from an active catalyst site in a facile manner. In contrastto a shuttling agent, a “chain transfer agent” causes termination ofpolymer chain growth and amounts to a one-time transfer of growingpolymer from the catalyst to the transfer agent. Desirably, theintermediate formed between the chain shuttling agent and the polymerylchain is sufficiently stable that chain termination is relatively rare.

The term, “multi-centered shuttling agent” refers to a compound ormolecule containing more than one, preferably 2 or 3, chain shuttlingmoieties joined by a polyvalent linking group. In practice, suitablechain shuttling moieties preferably include metal centers derived from ametal selected from Groups 2-14 of the Periodic Table of the Elementsand having one or more available valencies able to reversibly bind to agrowing polymer chain prepared by a coordination polymerizationcatalyst. At the same time that the chain shuttling moiety binds to thegrowing polymer chain, the remnant of the polyvalent linking groupremaining after loss of the chain shuttling moiety or moietiesincorporates or otherwise bonds to one or more active catalyst sites,thereby forming a catalyst composition containing an active coordinationpolymerization site capable of polymer insertion at least one terminusof what was originally the polyvalent linking group. Desirably, at least0.5 percent, preferably at least 1 percent, more preferably at least 2percent and most preferably at least 3 percent and up to 99 percent,preferably up to 98 percent, and more preferably up to 95 percent of thetotal polymer comprises a higher molecular weight polymer component.Particularly desirable compositions are blends of two polymers preparedaccording to the invention in which 25, 50 or 75 percent of the totalblend is the higher molecular weight component.

While attached to the growing polymer chain, the shuttling agentdesirably does not alter the polymer structure or incorporate additionalmonomer. That is, the shuttling agent does not also possess significantcatalytic properties for polymerization. Rather, the shuttling agentforms a metal-alkyl or other type interaction with the polymer moietyuntil transfer of the polymer moiety to an active polymerizationcatalyst site again occurs. Transfer of the same shuttling agent siteback to the original catalyst merely results in an increase in polymermolecular weight. Transfer to a different catalyst (if more than onecatalyst type is employed) results in formation of a distinguishablepolymer type, due for example, to a difference in monomer incorporationproperties, tacticity, or other property of the subsequent catalyst.Transfer by means of one of the remaining shuttling sites results instep growth from a different point in the polymer molecule. With atwo-centered shuttling agent, at least some of the resulting polymer isapproximately double the molecular weight of remaining polymer segments.Under certain circumstances, the subsequently formed polymer region alsopossesses a distinguishable physical or chemical property, such as adifferent monomer or comonomer identity, a difference in comonomercomposition distribution, crystallinity, density, tacticity,regio-error, or other property, compared to the polymer formed at othertimes during the polymerization. Subsequent repetitions of the foregoingprocess can result in formation of segments or blocks having amultiplicity of differing properties, or a repetition of a previouslyformed polymer composition, depending on the rates of polymerylexchange, number of reactors or zones within a reactor, transportbetween the reactors or zones, number of different catalysts, monomergradient in the reactor(s), and so forth. The polymers of the inventionmay be characterized by either a narrow or a broad molecular weightdistribution. Polymers having a narrow molecular weight distributiontypically have a PDI (Mw/Mn) from 2.0 to 2.8. Polymers having a broadPDI are those with PDI from 2.8 to 20, more preferably from 3.0 to 10.

The process of the invention employing a two-centered chain shuttlingagent and single catalyst may be further elucidated by reference to FIG.1, where there is illustrated an activated catalyst, 10, and amulti-centered shuttling agent, 14, containing two separate chainshuttling sites, M. Under chain growth polymerization conditions theactivated catalyst forms a polymer chain, 12. In step 1, the shuttlingagent exchanges one chain shuttling moiety with a catalyst/polymercombination, thereby binding the polymer chain, 12, to a chain shuttlingmoiety, M. Simultaneously, the remnant of the chain shuttling agent, 14,resulting from loss of a moiety, M, attaches to an active catalyst site,forming a new species, 11, capable of continued polymerization. In step2, new polymer segment, 12a is produced by the catalyst site, therebyforming a polymer segment joined to chain shuttling remnant, 14. Nochain growth occurs at the other species of the reaction, the polymerchain, 12 terminated with chain shuttling agent remnant, M. In step 3,chain transfer followed by polymerization occurs thereby forming a newpolymer segment, 12b, attached to original polymer segment 12, andregeneration of a two centered chain shuttling MSA including polymerextension 12a attached to moiety 14 and two M moieties. In step 4, afinal transfer of this two centered chain shuttling MSA via the secondshuttling center results in formation of active catalyst attached to thecombined MSA moiety, 14 and polymer segment 12a and separate polymersegment 12 joined to polymer segment 12b. Although depicted as separatepolymer regions, it is to be understood that the two polymers 12 and 12bformed under nearly identical polymerization conditions by the samecatalyst species are substantially identical, and under homogeneouspolymerization conditions, the combination of polymer 12 and 12b isessentially indistinguishable from polymer 12 itself. In step 5, newpolymer segment, 12c is formed at the active catalyst site attached toMSA remnant 14. Termination in step 6 results in formation of twopolymer products, 18 and 19, which are distinguishable based onmolecular weight as well as the presence of the residue of thetwo-centered chain shuttling agent, 14, in polymer product 18.

Transfer of the growing polymer may occur multiple times with continuedgrowth of the polymer segment each time it is attached to an activecatalyst. Under uniform polymerization conditions, the growing polymerblocks are substantially-homogeneous, though their size conforms to adistribution of sizes, desirably a most probable distribution. Ifdiffering polymerization conditions such as the presence of differentmonomers or monomer gradients in a reactor, multiple reactors operatingunder differing process conditions, and so forth, the respective polymersegments may also be distinguished based on differences in chemical orphysical properties. Chain shuttling and further growth may continue inthe foregoing manner for any number of cycles. However, the resultingproduct mixture contains at least two separate species distinguishableprimarily based on molecular weight difference, with polymer species 18,containing the remnant of the multi-centered shuttling agent, 14, beingapproximately double the size of polymer product, 19. Accordingly, inthis instance a product of substantially homogeneous composition andhaving a bimodal molecular weight distribution is formed.

In FIG. 2 a similar, but less prevalent process is illustrated whereinsimultaneous growth at both centers of a two centered MSA takes place.In particular, an activated catalyst, 20, and a multi-centered shuttlingagent, 24 containing two separate chain shuttling sites, M are presentin a reactor operating under polymerization conditions. The catalystforms a polymer segment 22. In step 1, the shuttling agent exchanges oneof the two active sites with the catalyst/polymer combination, therebyforming a species comprising the polymer chain, 22 attached to M.Simultaneously, the remnant of the chain shuttling agent, 24-M attachesto an active catalyst site, forming a new species, 21, capable ofcontinued polymerization. In step 2, new polymer segment, 22a isproduced by the catalyst site, thereby forming a polymer segment joinedto chain shuttling remnant, 24. In step 3, chain transfer and growthinvolving the remaining site of the two centered MSA occurs while stillattached to the original catalyst, thereby forming a polymer species, 26having two active catalyst sites separated by polymer segment 22a andshuttling agent remnant, 24. In step 4, continued polymerization fromboth active sites forms a polymeric species, 27 containing two regionsof polymer growth, 22a and 22b joined by the remnant of the two-centeredshuttling agent, 24 with active catalyst sites on each end. Terminationof chain growth in step 5 results in formation of two polymer products,28 and 29, which are distinguishable based on molecular weight as wellas the presence of the residue of the two-centered chain shuttlingagent, 24, in polymer product 28.

The process of the invention employing a two-centered chain shuttlingagent and two different catalysts, C′ and C″, is illustrated in FIG. 3,where a first activated catalyst, C′, forms a polymer chain, 32. Thesecond activated catalyst, C″, also forms a polymer segment which is notdepicted. In step 1, the shuttling agent exchanges one chain shuttlingmoiety with a catalyst/polymer combination, thereby binding the polymerchain, 32, to a chain shuttling moiety, M. Simultaneously, the remnantof the chain shuttling agent, 34 resulting from loss of a moiety, M,attaches to an active catalyst site, forming a new species, 31, capableof continued polymerization. In step 2, new polymer segment, 32a isproduced by the catalyst site, thereby forming a polymer segment joinedto the remnant of multi-centered shuttling remnant, 34. No chain growthoccurs at the shuttling agent terminated polymer chain, 32. In step 3,chain transfer occurs involving the second catalyst, C″, followed bypolymerization to form a polymeric species, 35, comprising polymersegment, 36 attached to originally formed polymer chain 32. Polymersegment, 36 has different polymer properties such as comonomerincorporation or tacticity from polymer segment 32 or 32a. In step 4,chain transfer occurs once again, involving both catalyst C′ and C″.Continued polymerization from both catalyst sites in step 5 forms newpolymer segments, 32b and 36a, also having different polymer propertiessuch as comonomer incorporation or tacticity. These polymer segments areeach joined by the remnant of the two-centered shuttling agent, 34 topolymer segment 32a. Termination in step 6 results in formation of threepolymer products, 38 and 39, and 40, which are distinguishable based onmolecular weight as well as the presence of the residue of thetwo-centered chain shuttling agent, 34, in polymer products 38 and 40.In addition, products 38 and 39 are pseudo-block copolymers due to thepresence of differing polymer regions formed by the respective catalystsC′ and C″. Additional polymer formed solely from catalyst C′ or C″ (notillustrated) may be present in the product mixture as well.

In FIG. 4, a variation of the foregoing process employing two catalystsC and C′ in the polymerization of ethylene, 1 and a C₃₋₂₀ α-olefin(T=C₁₋₁₈ hydrocarbyl), 2 in the presence of a dicentered shuttlingagent, 3, having a divalent linking group, L, joining two chainshuttling moieties, M¹ and M² is illustrated. The shuttling moieties, M¹and M² have differing affinities with respect to the catalysts, C andC′. In particular, M¹ is more inclined to engage in polymer transferwith catalyst C whereas M² has a higher reactivity (increased shuttlingindex) with catalyst C′. In the various chain shuttling steps 1) and 3)shuttling between M¹ and catalyst C as well as between M² and catalystC′ are illustrated. The skilled artisan will appreciate that the varioussteps illustrated may occur in any order. By also selecting thecatalysts C and C′ with respect to their ability or inability toincorporate comonomer (or otherwise produce distinguishable polymers),the polymer segments formed by the respective catalysts. 4 and 5, willpossess distinct physical properties and the resulting product will be adiblock copolymer. In particular, a diblock copolymer having one blockof a highly crystalline ethylene or propylene polymer (little or nocomonomer incorporation) and the other of an amorphous ethylene orpropylene copolymer (greater quantity of comonomer incorporation) may bereadily prepared in this manner.

The skilled artisan will appreciate that by employing multiplecatalysts, multiple monomers, multiple shuttling agents (including bothCSA and MSA types) and/or multiple reactors or variable reactorconditions, multitudinous combinations of reaction products areattainable.

The polymer product may be recovered by termination, such as by reactionwith water or other proton source, or functionalized, if desired,forming vinyl, hydroxyl, silane, carboxylic acid, carboxylic acid ester,ionomeric, or other functional terminal groups, especially to replacethe chain shuttling agent. Alternatively, the polymer segments may becoupled with a polyfunctional coupling agent, especially a difunctionalcoupling agent such as tolylene diisocyanate, dichlorodimethylsilane orethylenedichloride, and recovered.

Application of the foregoing techniques to the preparation of lowmolecular weight α,ω-terminally functionalized polymers, especiallyα,ω-diols, or α,ω-dienes, is disclosed in the following schematicillustration:

where an α,ω-two centered MSA, (PrMLMPr) containing two metal sites, M,such as Zn, joined by a divalent ligand group, L (such as ahydrocarbylene group) and substituted with protecting groups Pr, such astrimethylsilyl groups, which optionally may be joined together asindicated by dotted lines, is added to an ethylene polymerizationprocess. A metal di-terminated polymer is formed in the reaction whichmay be converted by known techniques (such as oxidation or displacement)to the corresponding dihydroxyl- or divinyl-functionalized polymerproducts using conventional processes. Suitable techniques forconversion of metallated polymers via displacement reactions aredisclosed in J. Am. Chem. Soc. 126, 10701-10712 (2004), J. Am. Chem.Soc. 127, 10166-10167 (2005), and references cited therein.

The skilled artisan will readily appreciate that the foregoing processmay employ a multi-centered shuttling agent initially containing 2, 3, 4or even more active centers, resulting in the formation of polymermixtures containing some quantity of a polymer that has approximatelydouble, triple, quadruple, or other multiple of the molecular weight ofthe remaining polymer and a star or branched morphology.

Ideally, the rate of chain shuttling is equivalent to or faster than therate of polymer termination, even up to 10 or even 100 times faster thanthe rate of polymer termination and significant with respect to the rateof polymerization. This permits formation of significant quantities ofpolymer chains terminated with chain shuttling agents and capable ofcontinued monomer insertion leading to significant quantities of thehigher molecular weight polymer.

By selecting different shuttling agents or mixtures of agents with acatalyst, by altering the comonomer composition, temperature, pressure,optional chain terminating agent such as H₂, or other reactionconditions in separate reactors or zones of a reactor operating underplug flow conditions, polymer products having segments of varyingdensity or comonomer concentration, monomer content, and/or otherdistinguishing property can be prepared, as well. For example, in atypical process employing two continuous solution polymerizationreactors connected in series and operating under differingpolymerization conditions, the resulting polymer segments will each havea relatively broad molecular weight distribution characteristic oftypical olefin coordination polymerization catalysts, preferably a Mw/Mnfrom 1.2 to 10, more preferably from 1.5 to 5.0, but will reflectdiffering polymerization conditions of their formation. In addition,certain quantities of a conventional random copolymer may also be formedcoincident with formation of the present polymer composition, resultingin a resin blend. If a relatively fast shuttling agent is employed, acopolymer having shorter block lengths but more uniform composition isobtained, with little formation of random copolymer. By proper selectionof both catalyst and multi-centered shuttling agent, relatively puremixtures of two polymers differing in molecular weight by approximatelyan integer value, copolymers containing relatively large polymersegments or blocks approximating true block copolymers, or blends of theforegoing with more random copolymers can all be obtained.

Highly desired polymer compositions according to the present inventioncomprise a polyolefin, especially a copolymer of ethylene and a C₃₋₈comonomer alone or in admixture with a homopolymer of ethylene or ahomopolymer of propylene, said composition having a distinct bimodalmolecular weight distribution, the higher molecular weight componenthaving a Mw approximately double or triple that of the lower molecularweigh component.

Suitable chain shuttling agents, if employed in addition to amulti-centered shuttling agent, include metal compounds or complexes ofmetals of Groups 1-13, preferably Group 1, 2, 12 or 13 of the PeriodicTable of the Elements, containing at least one C₁₋₂₀ hydrocarbyl group,preferably hydrocarbyl substituted aluminum, gallium or zinc compoundscontaining from 1 to 12 carbons in each hydrocarbyl group, and reactionproducts thereof with a proton source. Preferred hydrocarbyl groups arealkyl groups, preferably linear or branched, C₂₋₈ alkyl groups. Mostpreferred shuttling agents for use in the present invention are trialkylaluminum and dialkyl zinc compounds, especially triethylaluminum,tri(i-propyl) aluminum, tri(i-butyl)aluminum, tri(n-hexyl)aluminum,tri(n-octyl)aluminum, triethylgallium, or diethylzinc. Additionalsuitable shuttling agents include the reaction product or mixture formedby combining the foregoing organometal compound, preferably a tri(C₁₋₈)alkyl aluminum or di(C₁₋₈) alkyl zinc compound, especiallytriethylaluminum, tri(i-propyl) aluminum, tri(i-butyl)aluminum,tri(n-hexyl)aluminum, tri(n-octyl)aluminum, or diethylzinc, with lessthan a stoichiometric quantity (relative to the number of hydrocarbylgroups) of a secondary amine or a hydroxyl compound, especiallybis(trimethylsilyl)amine, t-butyl(dimethyl)siloxane,2-hydroxymethylpyridine, di(n-pentyl)amine, 2,6-di(t-butyl)phenol,ethyl(1-naphthyl)amine, bis(2,3,6,7-dibenzo-1-azacycloheptaneamine), or2,6-diphenylphenol. Desirably, sufficient amine or hydroxyl reagent isused such that one hydrocarbyl group remains per metal atom. The primaryreaction products of the foregoing combinations most desired for use inthe present invention as shuttling agents are n-octylaluminumdi(bis(trimethylsilyl)amide), i-propylaluminumbis(dimethyl(t-butyl)siloxide), and n-octylaluminumdi(pyridinyl-2-methoxide), 1-butylaluminumbis(dimethyl(t-butyl)siloxane), 1-butylaluminumbis(di(trimethylsilyl)amide), n-octylaluminum di(pyridine-2-methoxide),1-butylaluminum bis(di(n-pentyl)amide), n-octylaluminumbis(2,6-di-t-butylphenoxide), n-octylaluminumdi(ethyl(1-naphthyl)amide), ethylaluminum bis(t-butyldimethylsiloxide),ethylaluminium di(bis(trimethylsilyl)amide), ethylaluminumbis(2,3,6,7-dibenzo-1-azaecycloheptaneamide), n-octylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide), n-octylaluminumbis(dimethyl(t-butyl)siloxide, ethylzinc (2,6-diphenylphenoxide), andethylzinc (t-butoxide).

Preferred chain shuttling agents possess the highest transfer rates ofpolymer transfer as well as the highest transfer efficiencies (reducedincidences of chain termination). Such shuttling agents may be used inreduced concentrations and still achieve the desired degree ofshuttling. Highly desirably, chain shuttling agents with a singleexchange site are employed due to the fact that the effective molecularweight of the polymer in the reactor is lowered, thereby reducingviscosity of the reaction mixture and consequently reducing operatingcosts.

Suitable multi-centered shuttling agents for use herein are compounds orcomplexes containing two or more chain shuttling moieties per moleculewhich are capable of forming reversible electronic interactions withpolymer chains prepared by a coordination polymerization catalyst. Inaddition, the remnant formed upon loss of the chain shuttling moietiesmust be capable of interaction with an active catalyst composition,ultimately resulting in polymer growth at two or more sites of theremnant. Preferred multi-centered shuttling agents are compoundscorresponding to the formula: (M′)_(m)A wherein M′ is a chain shuttlingmoiety, preferably a monovalent derivative of a chain shuttling agentformed by separation from a linking group, A, and m is an integer from 2to 6, preferably 2 or 3. Preferred A groups are organic groups,especially hydrocarbon or inertly substituted hydrocarbon groups, mostpreferably alkadiyl or alkatriyl groups and inertly substitutedderivatives thereof. A most preferred A group is C₂₋₂₀ hydrocarbadiyl.Specific examples of suitable M′ groups include monovalent Group 6-13metal containing radicals, especially zinc or aluminum containingradicals. Preferred M′ radicals are those of the formula -M″(P^(g))_(p),where M″ is the metal, P^(g) is an organic radical, and p is a numberfrom 1 to 5 indicating the number of P^(s) groups. Suitable P^(s) groupsare selected from hydrogen, halo, hydrocarbyl, dihydrocarbylamido,hydrocarbyloxy, dihydrocarbylphosphido, tri(hydrocarbyl)silyl,halo-substituted hydrocarbyl, halo-substituted ti(hydrocarbyl)silyl,Lewis base containing chelating derivatives of the foregoing, andneutral Lewis base chelating ligands, such as tetrahydrofuran oracetylacetonate.

Specific examples of the foregoing MSA's include:(1,2-ethylene)di(zincchloride), (1,2-ethylene)di(zincbromide),(1,2-ethylene)di(ethylzinc), (1,2-ethylene)bis((trimethyl)silylzinc),(1,4-butylene)di(zincchloride), (1,4-butylene)di(zincbromide),(1,4-butylene)di(ethylzinc), (1,4-butylene)bis((trimethyl)silylzinc),bis(1,2-ethylenedizinc), bis(1,3-propylenedizinc),bis(1,4-butylenedizinc), methyltri(1,2-ethylenezincbromide),(1,2-ethylene)bis(dichloroaluminum), and(1,2-ethylene)bis(diethylaluminum).

Catalysts

Suitable catalysts for use herein include any compound or combination ofcompounds that is adapted for preparing polymers of the desiredcomposition or type. Both heterogeneous and homogeneous catalysts may beemployed. Examples of heterogeneous catalysts include the well knownZiegler-Natta compositions, especially Group 4 metal halides supportedon Group 2 metal halides or mixed halides and alkoxides and the wellknown chromium or vanadium based catalysts. Preferably however, for easeof use and for production of narrow molecular weight polymer segments insolution, the catalysts for use herein are homogeneous catalystscomprising a relatively pure organometallic compound or metal complex,especially compounds or complexes based on metals selected from Groups3-15 or the Lanthanide series of the Periodic Table of the Elements.

Preferred metal complexes for use herein include complexes of metalsselected from Groups 3 to 15 of the Periodic Table of the Elementscontaining one or more delocalized, π-bonded ligands or polyvalent Lewisbase ligands. Examples include metallocene, half-metallocene,constrained geometry, and polyvalent pyridylamine, or otherpolychelating base complexes. The complexes are generically depicted bythe formula: MK_(k)X_(x)Z_(z), or a dimer thereof, wherein

M is a metal selected from Groups 3-15, preferably 3-10, more preferably4-10, and most preferably Group 4 of the Periodic Table of the Elements;

K independently each occurrence is a group containing delocalizedπ-electrons or one or more electron pairs through which K is bound to M,said K group containing up to 50 atoms not counting hydrogen atoms,optionally two or more K groups may be joined together forming a bridgedstructure, and further optionally one or more K groups may be bound toZ, to X or to both Z and X;

X independently each occurrence is a monovalent, anionic moiety havingup to 40 non-hydrogen atoms, optionally one or more X groups may bebonded together thereby forming a divalent or polyvalent anionic group,and, further optionally, one or more X groups and one or more Z groupsmay be bonded together thereby forming a moiety that is both covalentlybound to M and coordinated thereto;

Z independently each occurrence is a neutral, Lewis base donor ligand ofup to 50 non-hydrogen atoms containing at least one unshared electronpair through which Z is coordinated to M;

k is an integer from 0 to 3;

x is an integer from 1 to 4;

z is a number from 0 to 3; and

the sum, k+x, is equal to the formal oxidation state of M.

Suitable metal complexes include those containing from 1 to 3 π-bondedanionic or neutral ligand groups, which may be cyclic or non-cyclicdelocalized 1-bonded anionic ligand groups. Exemplary of such 7-bondedgroups are conjugated or nonconjugated, cyclic or non-cyclic diene anddienyl groups, allyl groups, boratabenzene groups, phosphole, and arenegroups. By the term “π-bonded” is meant that the ligand group is bondedto the transition metal by a sharing of electrons from a partiallydelocalized π-bond.

Each atom in the delocalized π-bonded group may independently besubstituted with a radical selected from the group consisting ofhydrogen, halogen, hydrocarbyl, halohydrocarbyl, hydrocarbyl-substitutedheteroatoms wherein the heteroatom is selected from Group 14-16 of thePeriodic Table of the Elements, and such hydrocarbyl-substitutedheteroatom radicals further substituted with a Group 15 or 16 heteroatom containing moiety. In addition two or more such radicals maytogether form a fused ring system, including partially or fullyhydrogenated fused ring systems, or they may form a metallocycle withthe metal. Included within the term “hydrocarbyl” are C₁₋₂₀ straight,branched and cyclic alkyl radicals, C₆₋₂₀ aromatic radicals, C₇₋₂₀alkyl-substituted aromatic radicals, and C₇₋₂₀ aryl-substituted alkylradicals. Suitable hydrocarbyl-substituted heteroatom radicals includemono-, di- and tri-substituted radicals of boron, silicon, germanium,nitrogen, phosphorus or oxygen wherein each of the hydrocarbyl groupscontains from 1 to 20 carbon atoms. Examples include N,N-dimethylamino,pyrrolidinyl, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl,methyldi(t-butyl)silyl, triphenylgermyl, and trimethylgermyl groups.Examples of Group 15 or 16 hetero atom containing moieties includeamino, phosphino, alkoxy, or alkylthio moieties or divalent derivativesthereof, for example, amide, phosphide, alkyleneoxy or alkylenethiogroups bonded to the transition metal or Lanthanide metal, and bonded tothe hydrocarbyl group, π-bonded group, or hydrocarbyl-substitutedheteroatom.

Examples of suitable anionic, delocalized π-bonded groups includecyclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl,tetrahydrofluorenyl, octahydrofluorenyl, pentadienyl, cyclohexadienyl,dihydroanthracenyl, hexahydroanthracenyl, decahydroanthracenyl groups,phosphole, and boratabenzyl groups, as well as inertly substitutedderivatives thereof, especially C₁₋₁₀ hydrocarbyl-substituted ortris(C₁₋₁₀ hydrocarbyl)silyl-substituted derivatives thereof. Preferredanionic delocalized π-bonded groups are cyclopentadienyl,pentamethylcyclopentadienyl, tetramethylcyclopentadienyl,tetramethylsilylcyclopentadienyl, indenyl, 2,3-dimethylindenyl,fluorenyl, 2-methylindenyl, 2-methyl-4-phenylindenyl,tetrahydrofluorenyl, octahydrofluorenyl, 1-indacenyl,3-pyrrolidinoinden-1-yl, 3,4-(cyclopenta(l)phenanthren-1-yl, andtetrahydroindenyl.

The boratabenzenyl ligands are anionic ligands which are boroncontaining analogues to benzene. They are previously known in the arthaving been described by G. Herberich, et al., in Organometallics, 14,1, 471-480 (1995). Preferred boratabenzenyl ligands correspond to theformula:

wherein R¹ is an inert substituent, preferably selected from the groupconsisting of hydrogen, hydrocarbyl, silyl, halo or germyl, said R¹having up to 20 atoms not counting hydrogen, and optionally two adjacentR¹ groups may be joined together. In complexes involving divalentderivatives of such delocalized π-bonded groups one atom thereof isbonded by means of a covalent bond or a covalently bonded divalent groupto another atom of the complex thereby forming a bridged system.

Phospholes are anionic ligands that are phosphorus containing analoguesto a cyclopentadienyl group. They are previously known in the art havingbeen described by WO 98/50392, and elsewhere. Preferred phospholeligands correspond to the formula:

wherein R¹ is as previously defined.

Preferred transition metal complexes for use herein correspond to theformula: MK_(k)X_(x)Z_(z), or a dimer thereof, wherein:

M is a Group 4 metal;

K is a group containing delocalized π-electrons through which K is boundto M, said K group containing up to 50 atoms not counting hydrogenatoms, optionally two K groups may be joined together forming a bridgedstructure, and further optionally one K may be bound to X or Z;

X each occurrence is a monovalent, anionic moiety having up to 40non-hydrogen atoms, optionally one or more X and one or more K groupsare bonded together to form a metallocycle, and further optionally oneor more X and one or more Z groups are bonded together thereby forming amoiety that is both covalently bound to M and coordinated thereto;

Z independently each occurrence is a neutral, Lewis base donor ligand ofup to 50 non-hydrogen atoms containing at least one unshared electronpair through which Z is coordinated to M;

k is an integer from 0 to 3;

x is an integer from 1 to 4;

z is a number from 0 to 3; and

the sum, k+x, is equal to the formal oxidation state of M.

Preferred complexes include those containing either one or two K groups.The latter complexes include those containing a bridging group linkingthe two K groups. Preferred bridging groups are those corresponding tothe formula (ER′₂)_(e) wherein E is silicon, germanium, tin, or carbon,R′ independently each occurrence is hydrogen or a group selected fromsilyl, hydrocarbyl, hydrocarbyloxy and combinations thereof, said R′having up to 30 carbon or silicon atoms, and e is 1 to 8. Preferably, R′independently each occurrence is methyl, ethyl, propyl, benzyl,tert-butyl, phenyl, methoxy, ethoxy or phenoxy.

Examples of the complexes containing two K groups are compoundscorresponding to the formula:

wherein:

M is titanium, zirconium or hafnium, preferably zirconium or hafnium, inthe +2 or +4 formal oxidation state;

R³ in each occurrence independently is selected from the groupconsisting of hydrogen, hydrocarbyl, silyl, germyl, cyano, halo andcombinations thereof, said R³ having up to 20 non-hydrogen atoms, oradjacent R³ groups together form a divalent derivative (that is, ahydrocarbadiyl, siladiyl or germadiyl group) thereby forming a fusedring system, and

X″ independently each occurrence is an anionic ligand group of up to 40non-hydrogen atoms, or two X″ groups together form a divalent anionicligand group of up to 40 non-hydrogen atoms or together are a conjugateddiene having from 4 to 30 non-hydrogen atoms bound by means ofdelocalized π-electrons to M, whereupon M is in the +2 formal oxidationstate, and

R′, E and e are as previously defined.

Exemplary bridged ligands containing two π-bonded groups are:dimethylbis(cyclopentadienyl)silane,dimethylbis(tetramethylcyclopentadienyl)silane,dimethylbis(2-ethylcyclopentadien-1-yl)silane,dimethylbis(2-t-butylcyclopentadien-1-yl)silane,2,2-bis(tetramethylcyclopentadienyl)propane,dimethylbis(inden-1-yl)silane, dimethylbis(tetrahydroinden-1-yl)silane,dimethylbis(fluoren-1-yl)silane,dimethylbis(tetrahydrofluoren-1-yl)silane,dimethylbis(2-methyl-4-phenylinden-1-yl)-silane,dimethylbis(2-methylinden-1-yl)silane,dimethyl(cyclopentadiethyl)(fluoren-1-yl)silane,dimethyl(cyclopentadienyl)(octalhydrofluoren-1-yl)silane,dimethyl(cyclopentadienyl)(tetrahydrofluoren-1-yl)silane,(1,1,2,2-tetramethyl)-1,2-bis(cyclopentadienyl)disilane,(1,2-bis(cyclopentadienyl)ethane, anddimethyl(cyclopentadienyl)-1-(fluoren-1-yl)methane.

Preferred X″ groups are selected from hydride, hydrocarbyl, silyl,germyl, halohydrocarbyl, halosilyl, silylhydrocarbyl andaminohydrocarbyl groups, or two X″ groups together form a divalentderivative of a conjugated diene or else together they form a neutral,7-bonded, conjugated diene. Most preferred X″ groups are C₁₋₂₀hydrocarbyl groups.

Examples of metal complexes of the foregoing formula suitable for use inthe present invention include:

bis(cyclopentadienyl)zirconiumdimethyl, bis(cyclopentadienyl)zirconiumdibenzyl, bis(cyclopentadienyl)zirconium methyl benzyl,bis(cyclopentadienyl)zirconium methyl phenyl,bis(cyclopentadienyl)zirconiumdiphenyl,bis(cyclopentadienyl)titanium-allyl,bis(cyclopentadienyl)zirconiummethylmethoxide,bis(cyclopentadienyl)zirconiummethylchloride,bis(pentamethylcyclopentadienyl)zirconiumdimethyl,bis(pentamethylcyclopentadienyl)titaniumdimethyl,bis(indenyl)zirconiumdimethyl, indenylfluorenylzirconiumdimethyl,bis(indenyl)zirconiummethyl(2-(dimethylamino)benzyl),bis(indenyl)zirconiummethyltrimethylsilyl,bis(tetrahydroindenyl)zirconiummethyltrimethylsilyl,bis(pentamethylcyclopentadienyl)zirconiummethylbenzyl,bis(pentamethylcyclopentadienyl)zirconiumdibenzyl,bis(pentamethylcyclopentadienyl)zirconiummethylmethoxide,bis(pentamethylcyclopentadienyl)zirconiummethylchloride,bis(methylethylcyclopentadienyl)zirconiumdimethyl,bis(butylcyclopentadienyl)zirconiumdibenzyl,bis(t-butylcyclopentadienyl)zirconiumdimethyl,bis(ethyltetramethylcyclopentadienyl)zirconiumdimethyl,bis(methylpropylcyclopentadienyl)zirconiumdibenzyl,bis(trimethylsilylcyclopenitadienyl)zirconiumdibenzyl,dimethylsilylbis(cyclopentadienyl)zirconiumdimethyl,dimethylsilylbis(tetramethylcyclopentadienyl)titanium (III) allyldimethylsilylbis(t-butylcyclopentadienyl)zirconiumdichloride,dimethylsilylbis(n-butylcyclopeitadieliyl)zirconiumdichloride,(methylenebis(tetramethylcyclopentadienyl)titanium(II)2-(dimethylamino)benzyl,(methylenebis(n-butylcyclopentadienyl)titanium(III)2-(dimethylamino)benzyl,dimethylsilylbis(indenyl)zirconiumbenzylchloride,dimethylsilylbis(2-methylindenyl)zirconiumdimethyl,dimethylsilylbis(2-methyl-4-phenylindenyl)zirconium dimethyl,dimethylsilylbis(2-methylindenyl)zirconium-1,4-diphenyl-1,3-butadiene,dimethylsilylbis(2-methyl-4-phenylindenyl)zirconium (II)1,4-diphenyl-1,3-butadiene,dimethylsilylbis(tetrahydroindenyl)zirconium(II)1,4-diphenyl-1,3-butadiene,dimethylsilylbis(tetramethylcyclopentadienyl)zirconium dimethyldimethylsilylbis(fluorenyl)zirconiumdimethyl,dimethylsilyl-bis(tetrahydrofluorenyl)zirconium bis(trimethylsilyl),(isopropylidene)(cyclopentadienyl)(fluorenyl)zirconiumdibenzyl, anddimethylsilyl(tetramethylcyclopentadienyl)(fluorenyl)zirconium dimethyl.

A further class of metal complexes utilized in the present inventioncorresponds to the preceding formula: MKZ_(z)X_(x), or a dimer thereof,wherein M, K, X, x and z are as previously defined, and Z is asubstituent of up to 50 non-hydrogen atoms that together with K forms ametallocycle with M.

Preferred Z substituents include groups containing up to 30 non-hydrogenatoms comprising at least one atom that is oxygen, sulfur, boron or amember of Group 14 of the Periodic Table of the Elements directlyattached to K, and a different atom, selected from the group consistingof nitrogen, phosphorus, oxygen or sulfur that is covalently bonded toM.

More specifically this class of Group 4 metal complexes used accordingto the present invention includes “constrained geometry catalysts”corresponding to the formula:

wherein:

M is titanium or zirconium, preferably titanium in the +2, +3, or +4formal oxidation state;

K¹ is a delocalized, π-bonded ligand group optionally substituted withfrom 1 to 5 R² groups,

R² in each occurrence independently is selected from the groupconsisting of hydrogen, hydrocarbyl, silyl, germyl, cyano, halo andcombinations thereof, said R² having up to 20 non-hydrogen atoms, oradjacent R² groups together form a divalent derivative (that is, ahydrocarbadiyl, siladiyl or germadiyl group) thereby forming a fusedring system,

each X is a halo, hydrocarbyl, hydrocarbyloxy or silyl group, said grouphaving up to 20 non-hydrogen atoms, or two X groups together form aneutral C₅₋₃₀ conjugated diene or a divalent derivative thereof;

x is 1 or 2;

Y is —O—, —S—, —NR′—, —PR′—; and

X′ is SiR′₂, CR′₂, SiR′₂SiR′₂, CR′₂CR′₂, CR′═CR′, CR′₂SiR′₂, or GeR′₂,wherein

R′ independently each occurrence is hydrogen or a group selected fromsilyl, hydrocarbyl, hydrocarbyloxy and combinations thereof, said R′having up to 30 carbon or silicon atoms.

Specific examples of the foregoing constrained geometry metal complexesinclude compounds corresponding to the formula:

wherein,

Ar is an aryl group of from 6 to 30 atoms not counting hydrogen;

R⁴ independently each occurrence is hydrogen, Ar, or a group other thanAr selected from hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylgermyl,halide, hydrocarbyloxy, trihydrocarbylsiloxy,bis(trihydrocarbylsilyl)amino, di(hydrocarbyl)amino,hydrocarbadiylamino, hydrocarbylimino, di(hydrocarbyl)phosphino,hydrocarbadiylphosphino, hydrocarbylsulfido, halo-substitutedhydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl,trihydrocarbylsilyl-substituted hydrocarbyl,trihydrocarbylsiloxy-substituted hydrocarbyl,bis(trihydrocarbylsilyl)amino-substituted hydrocarbyl,di(hydrocarbyl)amino-substituted hydrocarbyl,hydrocarbyleneamino-substituted hydrocarbyl,di(hydrocarbyl)phosphino-substituted hydrocarbyl,hydrocarbylenephosphino-substituted hydrocarbyl, orhydrocarbylsulfido-substituted hydrocarbyl, said R group having up to 40atoms not counting hydrogen atoms, and optionally two adjacent R⁴ groupsmay be joined together forming a polycyclic fused ring group;

M is titanium;

X′ is SiR⁶ ₂, CR⁶ ₂, SiR⁶ ₂R⁶ ₂, CR⁶ ₂CR⁶ ₂, CR⁶═CR⁶, CR⁶ ₂SiR⁶ ₂, BR⁶,BR⁶L″, or GeR⁶ ₂;

Y is —O—, —S—, —NR—, —PR⁵—; —NR⁵ ₂, or —PR⁵ ₂;

R⁵, independently each occurrence, is hydrocarbyl, trihydrocarbylsilyl,or trihydrocarbylsilylhydrocarbyl, said R⁵ having up to 20 atoms otherthan hydrogen, and optionally two R⁵ groups or R⁵ together with Y or Zform a ring system;

R⁶, independently each occurrence, is hydrogen, or a member selectedfrom hydrocarbyl, hydrocarbyloxy, silyl, halogenated alkyl, halogenatedaryl, —NR⁵ ₂, and combinations thereof, said R⁶ having up to 20non-hydrogen atoms, and optionally, two R⁶ groups or R⁶ together with Zforms a ring system;

Z is a neutral diene or a monodentate or polydentate Lewis baseoptionally bonded to R⁵, R⁶, or X;

X is hydrogen, a monovalent anionic ligand group having up to 60 atomsnot counting hydrogen, or two X groups are joined together therebyforming a divalent ligand group;

x is 1 or 2; and

z is 0, 1 or 2.

Preferred examples of the foregoing metal complexes are substituted atboth the 3- and 4-positions of a cyclopentadienyl or indenyl group withan Ar group.

Examples of the foregoing metal complexes include:

-   (3-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,3-diphenyl-1,3-butadiene;-   (3-(pyrrol-1-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-(pyrrol-1-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-(pyrrol-1-yl)cyclopentadien-1-yl))dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3-(1    methylpyrrol-3-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-(1-methylpyrrol-3-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-(1-methylpyrrol-3-yl(cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3,4-diphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3,4-diphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3,4-diphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,3-pentadiene;-   (3-(3-N,N-dimethylamino)phenyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-(3-N,N-dimethylamino)phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-(3-N,N-dimethylamino)phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3-(4-methoxyphenyl)-4-methylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-(4-methoxyphenyl)-4-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-4-methoxyphenyl)-4-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium-dichloride,-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3-phenyl-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-phenyl-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-phenyl-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   2-methyl-(3,4-di(4-methylphenyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   2-methyl-(3,4-di(4-methylphenyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   2-methyl-(3,4-di(4-methylphenyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   ((2,3-diphenyl)-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silane    titanium dichloride,-   ((2,3-diphenyl)-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silane    titanium dimethyl,-   ((2,3-diphenyl)-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (2,3,4-triphenyl-5-methylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (2,3,4-triphenyl-5-methylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (2,3,4-triphenyl-5-methylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (2,3-diphenyl-4-(n-butyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (2,3-diphenyl-4-(n-butyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (2,3-diphenyl-4-(n-butyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (2,3,4,5-tetraphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (2,3,4,5-tetraphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl, and-   (2,3,4,5-tetraphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene.

Additional examples of suitable metal complexes for use herein arepolycyclic complexes corresponding to the formula:

where M is titanium in the +2, +3 or +4 formal oxidation state;

R⁷ independently each occurrence is hydride, hydrocarbyl, silyl, germyl,halide, hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino,di(hydrocarbyl)amino, hydrocarbyleneamino, di(hydrocarbyl)phosphino,hydrocarbylene-phosphino, hydrocarbylsulfido, halo-substitutedhydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, silyl-substitutedhydrocarbyl, hydrocarbylsiloxy-substituted hydrocarbyl,hydrocarbylsilylamino-substituted hydrocarbyl,di(hydrocarbyl)amino-substituted hydrocarbyl,hydrocarbyleneamino-substituted hydrocarbyl,di(hydrocarbyl)phosphino-substituted hydrocarbyl,hydrocarbylene-phosphino-substituted hydrocarbyl, orhydrocarbylsulfido-substituted hydrocarbyl, said R⁷ group having up to40 atoms not counting hydrogen, and optionally two or more of theforegoing groups may together form a divalent derivative;

R⁸ is a divalent hydrocarbylene- or substituted hydrocarbylene groupforming a fused system with the remainder of the metal complex, said R⁸containing from 1 to 30 atoms not counting hydrogen;

X^(a) is a divalent moiety, or a moiety comprising one σ-bond and aneutral two electron pair able to form a coordinate-covalent bond to M,said X^(a) comprising boron, or a member of Group 14 of the PeriodicTable of the Elements, and also comprising nitrogen, phosphorus, sulfuror oxygen;

X is a monovalent anionic ligand group having up to 60 atoms exclusiveof the class of ligands that are cyclic, delocalized, 7-bound ligandgroups and optionally two X groups together form a divalent ligandgroup;

Z independently each occurrence is a neutral ligating compound having upto 20 atoms;

x is 0, 1 or 2; and

z is zero or 1.

Preferred examples of such complexes are 3-phenyl-substituteds-indecenyl complexes corresponding to the formula:

2,3-dimethyl-substituted s-indecenyl complexes corresponding to theformulas:

or 2-methyl-substituted s-indecenyl complexes corresponding to theformula:

Additional examples of metal complexes that are usefully employedaccording to the present invention include those of the formula:

Specific metal complexes include:

-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,4-diphenyl-1,3-butadiene,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,3-pentadiene,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (III) 2-(N,N-dimethylamino)benzyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dichloride,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dimethyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dibenzyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,4-diphenyl-1,3-butadiene,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,3-pentadiene,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (III) 2-(N,N-dimethylamino)benzyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dichloride,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dimethyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dibenzyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,4-diphenyl-1,3-butadiene,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,3-pentadiene,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (III) 2-(N,N,-dimethylamino)benzyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dichloride,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dimethyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dibenzyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,4-diphenyl-1,3-butadiene,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,3-pentadiene,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (III) 2-(N,N-dimethylamino)benzyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dichloride,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dimethyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dibenzyl, and mixtures thereof, especially mixtures of    positional isomers.

Further illustrative examples of metal complexes for use according tothe present invention correspond to the formula:

where M is titanium in the +2, +3 or +4 formal oxidation state;

T is —NR⁹— or —O—;

R⁹ is hydrocarbyl, silyl, germyl, dihydrocarbylbutyl, or halohydrocarbylor up to 10 atoms not counting hydrogen;

R¹⁰ independently each occurrence is hydrogen, hydrocarbyl,trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, germyl, halide,hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino,di(hydrocarbyl)amino, hydrocarbyleneamino, di(hydrocarbyl)phosphino,hydrocarbylene-phosphino, hydrocarbylsulfido, halo-substitutedhydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, silyl-substitutedhydrocarbyl, hydrocarbylsiloxy-substituted hydrocarbyl,hydrocarbylsilylamino-substituted hydrocarbyl,di(hydrocarbyl)amino-substituted hydrocarbyl,hydrocarbyleneamino-substituted hydrocarbyl,di(hydrocarbyl)phosphino-substituted hydrocarbyl,hydrocarbylenephosphino-substituted hydrocarbyl, orhydrocarbylsulfido-substituted hydrocarbyl, said R¹⁰ group having up to40 atoms not counting hydrogen atoms, and optionally two or more of theforegoing adjacent R¹⁰ groups may together form a divalent derivativethereby forming a saturated or unsaturated fused ring;

X^(a) is a divalent moiety lacking in delocalized π-electrons, or such amoiety comprising one σ-bond and a neutral two electron pair able toform a coordinate-covalent bond to M, said X′ comprising boron, or amember of Group 14 of the Periodic Table of the Elements, and alsocomprising nitrogen, phosphorus, sulfur or oxygen;

X is a monovalent anionic ligand group having up to 60 atoms exclusiveof the class of ligands that are cyclic ligand groups bound to M throughdelocalized π-electrons or two X groups together are a divalent anionicligand group;

Z independently each occurrence is a neutral ligating compound having upto 20 atoms;

x is 0, 1, 2, or 3; and

z is 0 or 1.

Highly preferably T is ═N(CH₃), X is halo or hydrocarbyl, x is 2, X′ isdimethylsilane, z is 0, and R¹⁰ each occurrence is hydrogen, ahydrocarbyl, hydrocarbyloxy, dihydrocarbylamino, hydrocarbyleneamino,dihydrocarbylamino-substituted hydrocarbyl group, orhydrocarbyleneamino-substituted hydrocarbyl group of up to 20 atoms notcounting hydrogen, and optionally two R¹⁰ groups may be joined together.

Illustrative metal complexes of the foregoing formula that may beemployed in the practice of the present invention further include thefollowing compounds:

-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,3-pentadiene,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (III)    2-(N,N-dimethylamino)benzyl,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dichloride,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dimethyl,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dibenzyl,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    bis(trimethylsilyl),-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,3-pentadiene,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (III)    2-(N,N-dimethylamino)benzyl,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dichloride,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dimethyl,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dibenzyl,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    bis(trimethylsilyl),-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,3-pentadiene,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (III)    2-(N,N-dimethylamino)benzyl,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dichloride,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dimethyl,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dibenzyl,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    bis(trimethylsilyl),-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,3-pentadiene,-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (III)    2-(N,N-dimethylamino)benzyl,-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dichloride,-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dimethyl,-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dibenzyl; and-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    bis(trimethylsilyl).

Illustrative Group 4 metal complexes that may be employed in thepractice of the present invention further include:

-   (tert-butylamido)(1,1-dimethyl-2,3,4,9,10-η-1,4,5,6,7,8-hexahydronaphthalenyl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(1,1,2,3-tetramethyl-2,3,4,9,10-η-1,4,5,6,7,8-hexahydronaphthalenyl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium    dibenzyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium    dimethyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitanium    dimethyl,-   (tert-butylamido)(tetramethyl-η⁵-indenyl)dimethylsilanetitanium    dimethyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilane    titanium (III) 2-(dimethylamino)benzyl;-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (III)    allyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (III)    2,4-dimethylpentadienyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (II)    1,3-pentadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (II)    2,4-hexadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    2,3-dimethyl-1,3-butadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    isoprene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    1,3-butadiene,-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    2,3-dimethyl-1,3-butadiene,-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    isoprene-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    dimethyl-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    dibenzyl-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    1,3-butadiene,-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (II)    1,3-pentadiene,-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (II)    1,3-pentadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    dimethyl,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    dibenzyl,-   (tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium (II)    1,3-pentadiene,-   (tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium (II)    2,4-hexadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethyl-silanetitanium (IV)    1,3-butadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (IV)    2,3-dimethyl-1,3-butadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (IV)    isoprene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethyl-silanetitanium (II)    1,4-dibenzyl-1,3-butadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (II)    2,4-hexadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethyl-silanetitanium (II)    3-methyl-1,3-pentadiene,-   (tert-butylamido)(2,4-dimethylpentadien-3-yl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(6,6-dimethylcyclohexadienyl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(1,1-dimethyl-2,3,4,9,10-η-1,4,5,6,7,8-hexahydronaphthalen-4-yl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(1,1,2,3-tetramethyl-2,3,4,9,10-η-1,4,5,6,7,8-hexahydronaphthalen-4-yl)dimethylsilanetitaniumdimethyl-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl    methylphenylsilanetitanium (IV) dimethyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl    methylphenylsilanetitanium (II) 1,4-diphenyl-1,3-butadiene,-   1-(tert-butylamido)-2-(tetramethyl-η⁵-cyclopentadienyl)ethanediyltitanium (IV)    dimethyl, and-   1-(tert-butylamido)-2-(tetramethyl-η⁵-cyclopentadienyl)ethanediyl-titanium (II)    1,4-diphenyl-1,3-butadiene.

Other delocalized, π-bonded complexes, especially those containing otherGroup 4 metals, will, of course, be apparent to those skilled in theart, and are disclosed among other places in: WO 03/78480, WO 03/78483,WO 02/92610, WO 02/02577, US 2003/0004286 and U.S. Pat. Nos. 6,515,155,6,555,634, 6,150,297, 6,034,022, 6,268,444, 6,015,868, 5,866,704, and5,470,993.

Additional examples of metal complexes that are usefully employed hereininclude polyvalent Lewis base compounds corresponding to the formula:

wherein T^(b) is a bridging group, preferably containing 2 or more atomsother than hydrogen,

X^(b) and Y^(b) are each independently selected from the groupconsisting of nitrogen, sulfur, oxygen and phosphorus; more preferablyboth X^(b) and Y^(b) are nitrogen,

R^(b) and R^(b)′ independently each occurrence are hydrogen or C₁₋₅₀hydrocarbyl groups optionally containing one or more heteroatoms orinertly substituted derivative thereof. Non-limiting examples ofsuitable R^(b) and R^(b)′ groups include alkyl, alkenyl, aryl, aralkyl,(poly)alkylaryl and cycloalkyl groups, as well as nitrogen, phosphorus,oxygen and halogen substituted derivatives thereof. Specific examples ofsuitable Rb and Rb′ groups include methyl, ethyl, isopropyl, octyl,phenyl, 2,6-dimethylphenyl, 2,6-di(isopropyl)phenyl,2,4,6-trimethylphenyl, pentafluorophenyl, 3,5-trifluoromethylphenyl, andbenzyl;

g is 0 or 1;

M^(b) is a metallic element selected from Groups 3 to 15, or theLanthanide series of the Periodic Table of the Elements. Preferably,M^(b) is a Group 3-13 metal, more preferably M^(b) is a Group 4-10metal;

L^(b) is a monovalent, divalent, or trivalent anionic ligand containingfrom 1 to 50 atoms, not counting hydrogen. Examples of suitable L^(b)groups include halide; hydride; hydrocarbyl, hydrocarbyloxy;di(hydrocarbyl)amido, hydrocarbyleneamido, di(hydrocarbyl)phosphido;hydrocarbylsulfido; hydrocarbyloxy, tri(hydrocarbylsilyl)alkyl; andcarboxylates. More preferred L^(b) groups are C₁₋₂₀ alkyl, C₇₋₂₀aralkyl, and chloride;

h is an integer from 1 to 6, preferably from 1 to 4, more preferablyfrom 1 to 3, and j is 1 or 2, with the value h×j selected to providecharge balance;

Z^(b) is a neutral ligand group coordinated to M^(b), and containing upto 50 atoms not counting hydrogen Preferred Z^(b) groups includealiphatic and aromatic amines, phosphines, and ethers, alkenes,alkadienes, and inertly substituted derivatives thereof. Suitable inertsubstituents include halogen, alkoxy, aryloxy, alkoxycarbonyl,aryloxycarbonyl, di(hydrocarbyl)amine, tri(hydrocarbyl)silyl, andnitrile groups. Preferred Z^(b) groups include triphenylphosphine,tetrahydrofuran, pyridine, and 1,4-diphenylbutadiene;

f is an integer from 1 to 3;

two or three of T^(b), R^(b) and R^(b)′ may be joined together to form asingle or multiple ring structure;

h is an integer from 1 to 6, preferably from 1 to 4, more preferablyfrom 1 to 3;

indicates any form of electronic interaction comprising a net coulombicattraction, especially coordinate or covalent bonds, including multiplebonds;

arrows signify coordinate bonds; and

dotted lines indicate optional double bonds.

In one embodiment, it is preferred that R^(b) have relatively low sterichindrance with respect to X^(b). In this embodiment, most preferredR^(b) groups are straight chain alkyl groups, straight chain alkenylgroups, branched chain alkyl groups wherein the closest branching pointis at least 3 atoms removed from X^(b), and halo, dihydrocarbylamino,alkoxy or trihydrocarbylsilyl substituted derivatives thereof. Highlypreferred R^(b) groups in this embodiment are C₁₋₈ straight chain alkylgroups.

At the same time, in this embodiment R^(b)′ preferably has relativelyhigh steric hindrance with respect to Y^(b). Non-limiting examples ofsuitable R^(b)′ groups for this embodiment include alkyl or alkenylgroups containing one or more secondary or tertiary carbon centers,cycloalkyl, aryl, alkaryl, aliphatic or aromatic heterocyclic groups,organic or inorganic oligomeric, polymeric or cyclic groups, and halo,dihydrocarbylamino, alkoxy or trihydrocarbylsilyl substitutedderivatives thereof. Preferred R^(b)′ groups in this embodiment containfrom 3 to 40, more preferably from 3 to 30, and most preferably from 4to 20 atoms not counting hydrogen and are branched or cyclic.

Examples of preferred T^(b) groups are structures corresponding to thefollowing formulas:

wherein

Each R^(d) is C₁₋₁₀ hydrocarbyl group, preferably methyl, ethyl,n-propyl, i-propyl, t-butyl, phenyl, 2,6-dimethylphenyl, benzyl, ortolyl. Each R^(e) is C₁₋₁₀ hydrocarbyl, preferably methyl, ethyl,n-propyl, i-propyl, t-butyl, phenyl, 2,6-dimethylphenyl, benzyl, ortolyl. In addition, two or more R^(d) or R^(e) groups, or mixtures of Rdand Re groups may together form a polyvalent derivative of a hydrocarbylgroup, such as, 1,4-butylene, 1,5-pentylene, or a multicyclic, fusedring, polyvalent hydrocarbyl- or heterohydrocarbyl-group, such asnaphthalene-1,8-diyl.

Preferred examples of the foregoing polyvalent Lewis base complexesinclude:

wherein R^(d′) each occurrence is independently selected from the groupconsisting of hydrogen and C₁₋₅₀ hydrocarbyl groups optionallycontaining one or more heteroatoms, or inertly substituted derivativethereof, or further optionally, two adjacent R^(d′) groups may togetherform a divalent bridging group;

d′ is 4;

M^(b′) is a group 4 metal, preferably titanium or hafnium or a Group 10metal, preferably Ni or Pd;

L^(b′) is a monovalent ligand of up to 50 atoms not counting hydrogen,preferably halide or hydrocarbyl, or two L^(b′) groups together are adivalent or neutral ligand group, preferably a C₂₋₅₀ hydrocarbylene,hydrocarbadiyl or diene group.

The polyvalent Lewis base complexes for use in the present inventionespecially include Group 4 metal derivatives, especially hafniumderivatives of hydrocarbylamine substituted heteroaryl compoundscorresponding to the formula:

wherein:

R¹¹ is selected from alkyl, cycloalkyl, heteroalkyl, cycloheteroalkyl,aryl, and inertly substituted derivatives thereof containing from 1 to30 atoms not counting hydrogen or a divalent derivative thereof;

T¹ is a divalent bridging group of from 1 to 41 atoms other thanhydrogen, preferably 1 to 20 atoms other than hydrogen, and mostpreferably a mono- or di-C₁₋₂₀ hydrocarbyl substituted methylene orsilane group; and

R¹² is a C₅₋₂₀ heteroaryl group containing Lewis base functionality,especially a pyridin-2-yl- or substituted pyridin-2-yl group or adivalent derivative thereof;

M¹ is a Group 4 metal, preferably hafnium;

X¹ is an anionic, neutral or dianionic ligand group;

x′ is a number from 0 to 5 indicating the number of such X¹ groups; and

bonds, optional bonds and electron donative interactions are representedby lines, dotted lines and arrows respectively.

Preferred complexes are those wherein ligand formation results fromhydrogen elimination from the amine group and optionally from the lossof one or more additional groups, especially from R¹². In addition,electron donation from the Lewis base functionality, preferably anelectron pair, provides additional stability to the metal center.Preferred metal complexes correspond to the formula:

wherein

M¹, X¹, x′, R¹¹ and T¹ are as previously defined,

R¹³, R¹⁴, R¹⁵ and R¹¹ are hydrogen, halo, or an alkyl, cycloalkyl,heteroalkyl, heterocycloalkyl, aryl, or silyl group of up to 20 atomslot counting hydrogen, or adjacent R³, R¹⁴, R¹⁵ or R¹⁶ groups may bejoined together thereby forming fused ring derivatives, and

bonds, optional bonds and electron pair donative interactions arerepresented by lines, dotted lines and arrows respectively.

More preferred examples of the foregoing metal complexes correspond tothe formula:

wherein

M¹, X¹, and x′ are as previously defined,

R¹³, R¹⁴, R¹⁵ and R¹⁶ are as previously defined, preferably R¹³, R¹⁴,and R¹⁵ are hydrogen, or C₁₋₄ alkyl, and R¹⁶ is C₆₋₂₀ aryl, mostpreferably naphthalenyl;

R^(a) independently each occurrence is C₁₋₄ alkyl, and a is 1-5, mostpreferably R^(a) in two ortho-positions to the nitrogen is isopropyl ort-butyl;

R¹⁷ and R¹⁸ independently each occurrence are hydrogen, halogen, or aC₁₋₂₀ alkyl or aryl group, most preferably one of R¹⁷ and R¹⁸ ishydrogen and the other is a C₆₋₂₀ aryl group, especially 2-isopropyl,phenyl or a fused polycyclic aryl group, most preferably an anthracenylgroup, and

bonds, optional bonds and electron pair donative interactions arerepresented by lines, dotted lines and arrows respectively.

Highly preferred metal complexes for use herein correspond to theformula:

wherein X¹ each occurrence is halide, N,N-dimethylamido, or C₁₋₄ alkyl,and preferably each occurrence X¹ is methyl;

R^(f) independently each occurrence is hydrogen, halogen, C₁₋₂₀ alkyl,or C₆₋₂₀ aryl, or two adjacent R^(f) groups are joined together therebyforming a ring, and f is 1-5; and

R^(c) independently each occurrence is hydrogen, halogen, C₁₋₂₀ alkyl,or C₆₋₂₀ aryl, or two adjacent R^(c) groups are joined together therebyforming a ring, and c is 1-5.

Most highly preferred examples of metal complexes for use according tothe present invention are complexes of the following formulas:

wherein R^(x) is C₁₋₄ alkyl or cycloalkyl, preferably methyl, isopropyl,t-butyl or cyclohexyl; and

X¹ each occurrence is halide, N,N-dimethylamido, or C₁₋₄ alkyl,preferably methyl.

Examples of metal complexes usefully employed according to the presentinvention include:

-   [N-(2,6-di(1-methylethyl)phenyl)amido)(o-tolyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dimethyl;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(o-tolyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    di(N,N-dimethylamido);-   [N-(2,6-di(1-methylethyl)phenyl)amido)(o-tolyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dichloride;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dimethyl;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    di(N,N-dimethylamido);-   [N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dichloride;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(phenanthren-5-yl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dimethyl;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(phenanthren-5-yl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    di(N,N-dimethylamido); and-   [N-(2,6-di(1-methylethyl)phenyl)amido)(phenanthren-5-yl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dichloride.

Under the reaction conditions used to prepare the metal complexes usedin the present invention, the hydrogen of the 2-position of theα-naphthalene group substituted at the 6-position of the pyridin-2-ylgroup is subject to elimination, thereby uniquely forming metalcomplexes wherein the metal is covalently bonded to both the resultingamide group and to the 2-position of the α-naphthalenyl group, as wellas stabilized by coordination to the pyridinyl nitrogen atom through theelectron pair of the nitrogen atom.

Additional suitable metal complexes of polyvalent Lewis bases for useherein include compounds corresponding to the formula:

where:

R²⁰ is an aromatic or inertly substituted aromatic group containing from5 to 20 atoms not counting hydrogen, or a polyvalent derivative thereof;

T³ is a hydrocarbylene or silane group having from 1 to 20 atoms notcounting hydrogen, or an inertly substituted derivative thereof;

M³ is a Group 4 metal, preferably zirconium or hafnium;

G is an anionic, neutral or dianionic ligand group; preferably a halide,hydrocarbyl or dihydrocarbylamide group having up to 20 atoms notcounting hydrogen;

g is a number from 1 to 5 indicating the number of such G groups; and

bonds and electron donative interactions are represented by lines andarrows respectively.

Preferably, such complexes correspond to the formula:

wherein:

T³ is a divalent bridging group of from 2 to 20 atoms not countinghydrogen, preferably a substituted or unsubstituted, C₃₋₆ alkylenegroup; and

Ar² independently each occurrence is an arylene or an alkyl- oraryl-substituted arylene group of from 6 to 20 atoms not countinghydrogen;

M³ is a Group 4 metal, preferably hafnium or zirconium;

G independently each occurrence is an anionic, neutral or dianionicligand group;

g is a number from 1 to 5 indicating the number of such X groups; and

electron donative interactions are represented by arrows.

Preferred examples of metal complexes of foregoing formula include thefollowing compounds:

where M³ is Hf or Zr;

Ar⁴ is C₆₋₂₀ aryl or inertly substituted derivatives thereof, especially3,5-di(isopropyl)phenyl, 3,5-di(isobutyl)phenyl,dibenzo-1H-pyrrole-1-yl, or anthracen-5-yl, and

T⁴ independently each occurrence comprises a C₃₋₆ alkylene group, a C₃₋₆cycloalkylene group, or an inertly substituted derivative thereof;

R²¹ independently each occurrence is hydrogen, halo, hydrocarbyl,trihydrocarbylsilyl, or trihydrocarbylsilylhydrocarbyl of up to 50 atomsnot counting hydrogen; and

G, independently each occurrence is halo or a hydrocarbyl ortrihydrocarbylsilyl group of up to 20 atoms not counting hydrogen, or 2G groups together are a divalent derivative of the foregoing hydrocarbylor trihydrocarbylsilyl groups.

Especially preferred are compounds of the formula:

wherein Ar⁴ is 3,5-di(isopropyl)phenyl, 3,5-di(isobutyl)phenyl,dibenzo-1H-pyrrole-1-yl, or anthracen-5-yl,

R²¹ is hydrogen, halo, or C₁₋₄ alkyl, especially methyl

T⁴ is propan-1,3-diyl or butan-1,4-diyl, and

G is chloro, methyl or benzyl.

A most highly preferred metal complex of the foregoing formula is:

The foregoing polyvalent Lewis base complexes are conveniently preparedby standard metallation and ligand exchange procedures involving asource of the Group 4 metal and the neutral polyfunctional ligandsource. In addition, the complexes may also be prepared by means of anamide elimination and hydrocarbylation process starting from thecorresponding Group 4 metal tetraamide and a hydrocarbylating agent,such as trimethylaluminum. Other techniques may be used as well. Thesecomplexes are known from the disclosures of, among others, U.S. Pat.Nos. 6,320,005, 6,103,657, WO 02/38628, WO 03/40195, and US 04/0220050.

Additional suitable metal compounds for use herein include Group 4-10metal derivatives corresponding to the formula:

wherein

-   -   M² is a metal of Groups 4-10 of the Periodic Table of the        elements, preferably Group 4 metals, Ni(II) or Pd(II), most        preferably zirconium;    -   T² is a nitrogen, oxygen or phosphorus containing group;    -   X² is halo, hydrocarbyl, or hydrocarbyloxy;    -   t is one or two;    -   x″ is a number selected to provide charge balance;    -   and T² and N are linked by a bridging ligand.

Such catalysts have been previously disclosed in J. Am. Chem. Soc., 118,267-268 (1996), J. Am. Chem. Soc., 117, 6414-6415 (1995), andOrganometallics, 16, 1514-1516, (1997), among other disclosures.

Preferred examples of the foregoing metal complexes are aromatic diimineor aromatic dioxyimine complexes of Group 4 metals, especiallyzirconium, corresponding to the formula:

wherein;

M², X² and T² are as previously defined;

R^(d) independently each occurrence is hydrogen, halogen, or R^(e); and

R^(e) independently each occurrence is C₁₋₂₀ hydrocarbyl or aheteroatom-, especially a F, N, S or P-substituted derivative thereof,more preferably C₁₋₁₀ hydrocarbyl or a F or N substituted derivativethereof, most preferably alkyl, dialkylaminoalkyl, pyrrolyl,piperidenyl, perfluorophenyl, cycloalkyl, (poly)alkylaryl, or aralkyl.

Most preferred examples of the foregoing metal complexes are aromaticdioxyimine complexes of zirconium, corresponding to the formula:

wherein;

X² is as previously defined, preferably C₁₋₁₀ hydrocarbyl, mostpreferably methyl or benzyl; and

R^(e)′ is methyl, isopropyl, t-butyl, cyclopentyl, cyclohexyl,2-methylcyclohexyl, 2,4-dimethylcyclohexyl, 2-pyrrolyl,N-methyl-2-pyrrolyl, 2-piperidenyl, N-methyl-2-piperidenyl, benzyl,o-tolyl, 2,6-dimethylphenyl, perfluorophenyl, 2,6-di(isopropyl)phenyl,or 2,4,6-trimethylphenyl.

The foregoing complexes also include certain phosphinimine complexes aredisclosed in EP-A-890581. These complexes correspond to the formula:[(R^(f))₃—P═N]_(f)M(K²)(R^(f))_(3-f), wherein:

R^(f) is a monovalent ligand or two R^(f) groups together are a divalentligand, preferably R^(f) is hydrogen or C₁₋₄ alkyl;

M is a Group 4 metal,

K² is a group containing delocalized π-electrons through which K² isbound to M, said K² group containing up to 50 atoms not countinghydrogen atoms, and

f is 1 or 2.

Catalysts having high comonomer incorporation properties are also knownto reincorporate in situ prepared long chain olefins resultingincidentally during the polymerization through β-hydride elimination andchain termination of growing polymer, or other process. Theconcentration of such long chain olefins is particularly enhanced by useof continuous solution polymerization conditions at high conversions,especially ethylene conversions of 95 percent or greater, morepreferably at ethylene conversions of 97 percent or greater. Under suchconditions a small but detectable quantity of vinyl group terminatedpolymer may be reincorporated into a growing polymer chain, resulting inthe formation of long chain branches, that is, branches of a carbonlength greater than would result from other deliberately addedcomonomer. Moreover, such chains reflect the presence of othercomonomers present in the reaction mixture. That is, the chains mayinclude short chain or long chain branching as well, depending on thecomonomer composition of the reaction mixture. However, the presence ofan MSA or CSA during polymerization can seriously limit the incidence oflong chain branching since the vast majority of the polymer chainsbecome attached to an MSA or CSA species and are prevented fromundergoing β-hydride elimination.

Cocatalysts

Each of the metal complexes (also interchangeably referred to herein asprocatalysts) may be activated to form the active catalyst compositionby combination with a cocatalyst, preferably a cation formingcocatalyst, a strong Lewis acid, or a combination thereof.

Suitable cation forming cocatalysts include those previously known inthe art for use with Group 4 metal olefin polymerization complexes.Examples include neutral Lewis acids, such as C₁₋₃₀ hydrocarbylsubstituted Group 13 compounds, especially tri(hydrocarbyl)aluminum- ortri(hydrocarbyl)boron compounds and halogenated (includingperhalogenated) derivatives thereof, having from 1 to 10 carbons in eachhydrocarbyl or halogenated hydrocarbyl group, more especiallyperfluorinated tri(aryl)boron compounds, and most especiallytris(pentafluoro-phenyl)borane; nonpolymeric, compatible,noncoordinating, ion forming compounds (including the use of suchcompounds under oxidizing conditions), especially the use of ammonium-,phosphonium-, oxonium-, carbonium-, silylium- or sulfonium-salts ofcompatible, noncoordinating anions, or ferrocenium-, lead- or silversalts of compatible, noncoordinating anions; and combinations of theforegoing cation forming cocatalysts and techniques. The foregoingactivating cocatalysts and activating techniques have been previouslytaught with respect to different metal complexes for olefinpolymerizations in the following references: EP-A-277,003, U.S. Pat.Nos. 5,153,157, 5,064,802, 5,321,106, 5,721,185, 5,350,723, 5,425,872,5,625,087, 5,883,204, 5,919,983, 5,783,512, WO 99/15534, and WO99/42467.

Combinations of neutral Lewis acids, especially the combination of atrialkyl aluminum compound having from 1 to 4 carbons in each alkylgroup and a halogenated tri(hydrocarbyl)boron compound having from 1 to20 carbons in each hydrocarbyl group, especiallytris(pentafluorophenyl)borane, further combinations of such neutralLewis acid mixtures with a polymeric or oligomeric alumoxane, andcombinations of a single neutral Lewis acid, especiallytris(pentafluorophenyl)borane with a polymeric or oligomeric alumoxanemay be used as activating cocatalysts. Preferred molar ratios of metalcomplex:tris(pentafluorophenyl-borane:alumoxaiie are from 1:1:1 to1:5:20, more preferably from 1:1:1.5 to 1:5:10.

Suitable ion forming compounds useful as cocatalysts in one embodimentof the present invention comprise a cation which is a Bronsted acidcapable of donating a proton, and a compatible, noncoordinating anion,A⁻. As used herein, the term “noncoordinating” means an anion orsubstance which either does not coordinate to the Group 4 metalcontaining precursor complex and the catalytic derivative derived therefrom, or which is only weakly coordinated to such complexes therebyremaining sufficiently labile to be displaced by a neutral Lewis base. Anoncoordinating anion specifically refers to an anion which whenfunctioning as a charge balancing anion in a cationic metal complex doesnot transfer an anionic substituent or fragment thereof to said cationthereby forming neutral complexes. “Compatible anions” are anions whichare not degraded to neutrality when the initially formed complexdecomposes and are noninterfering with desired subsequent polymerizationor other uses of the complex.

Preferred anions are those containing a single coordination complexcomprising a charge-bearing metal or metalloid core which anion iscapable of balancing the charge of the active catalyst species (themetal cation) which may be formed when the two components are combined.Also, said anion should be sufficiently labile to be displaced byolefinic, diolefinic and acetylenically unsaturated compounds or otherneutral Lewis bases such as ethers or nitrites. Suitable metals include,but are not limited to, aluminum, gold and platinum. Suitable metalloidsinclude, but are not limited to, boron, phosphorus, and silicon.Compounds containing anions which comprise coordination complexescontaining a single metal or metalloid atom are, of course, well knownand many, particularly such compounds containing a single boron atom inthe anion portion, are available commercially.

Preferably such cocatalysts may be represented by the following generalformula:(L*−H)_(g) ⁺(A)_(g−)wherein:

L* is a neutral Lewis base;

(L*−H)⁺ is a conjugate Bronsted acid of L*;

A^(g−) is a noncoordinating, compatible anion having a charge of g−, and

g is an integer from 1 to 3.

More preferably A^(g−) corresponds to the formula: [MiQ₄]⁻;

wherein:

Mi is boron or aluminum in the +3 formal oxidation state; and

Q independently each occurrence is selected from hydride, dialkylamido,halide, hydrocarbyl, hydrocarbyloxide, halosubstituted-hydrocarbyl,halosubstituted hydrocarbyloxy, and halo-substituted silylhydrocarbylradicals (including perhalogenated hydrocarbyl-perhalogenatedhydrocarbyloxy- and perhalogenated silylhydrocarbyl radicals), said Qhaving up to 20 carbons with the proviso that in not more than oneoccurrence is Q halide. Examples of suitable hydrocarbyloxide Q groupsare disclosed in U.S. Pat. No. 5,296,433.

In a more preferred embodiment, d is one, that is, the counter ion has asingle negative charge and is A⁻. Activating cocatalysts comprisingboron which are particularly useful in the preparation of catalysts ofthis invention may be represented by the following general formula:(L*−H)⁺(BQ₄)⁻;wherein:

L* is as previously defined;

B is boron in a formal oxidation state of 3; and

Q is a hydrocarbyl-, hydrocarbyloxy-, fluorinated hydrocarbyl-,fluorinated hydrocarbyloxy-, or fluorinated silylhydrocarbyl- group ofup to 20 nonhydrogen atoms, with the proviso that in not more than oneoccasion is Q hydrocarbyl.

Preferred Lewis base salts are ammonium salts, more preferablytrialkylammonium salts containing one or more C₁₂₋₄₀ alkyl groups. Mostpreferably, Q is each occurrence a fluorinated aryl group, especially, apentafluorophenyl group.

Illustrative, but not limiting, examples of boron compounds which may beused as an activating cocatalyst in the preparation of the improvedcatalysts of this invention are tri-substituted ammonium salts such as:

trimethylammonium tetrakis(pentafluorophenyl)borate, triethylammoniumtetrakis(pentafluorophenyl)borate, tripropylammoniumtetrakis(pentafluorophenyl)borate, tri(n-butyl)ammoniumtetrakis(pentafluorophenyl)borate, tri(sec-butyl)ammoniumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumn-butyltris(pentafluorophenyl)borate, N,N-dimethylaniliniumbenzyltris(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis(4-(t-butyldimethylsilyl)-2,3,5,6-tetrafluorophenyl)borate,N,N-dimethylaniliniumtetrakis(4-(triisopropylsityl)-2,3,5,6-tetrafluorophenyl)borate,N,N-dimethylanilinium pentafluorophenoxytris(pentafluorophenyl) borate,N,N-diethylanilinium tetrakis(pentafluorophenyl)borate,N,N-dimethyl-2,4,6-trimethylanilinium tetrakis(pentafluorophenyl)borate,dimethyloctadecylammonium tetrakis(pentafluorophenyl)borate,methyldioctadecylammonium tetrakis(pentafluorophenyl)borate, dialkylammonium salts such as:

di-(i-propyl)ammonium tetrakis(pentafluorophenyl)borate,methyloctadecylammonium tetrakis(pentafluorophenyl)borate,methyloctadodecylaminonium tetrakis(pentafluorophenyl)borate, anddioctadecylammonium tetrakis(pentafluorophenyl)borate; tri-substitutedphosphonium salts such as:

triphenylphosphonium tetrakis(pentafluorophenyl)borate,methyldioctadecylphosphonium tetrakis(pentafluorophenyl)borate, andtri(2,6-dimethylphenyl)phosphonium tetrakis(pentafluorophenyl)borate;di-substituted oxonium salts such as:

diphenyloxonium tetrakis(pentafluorophenyl)borate, di(o-tolyl)oxoniumtetrakis(pentafluorophenyl)borate, and di(octadecyl)oxoniumtetrakis(pentafluorophenyl)borate; di-substituted sulfonium salts suchas:

di(o-tolyl)sulfonium tetrakis(pentafluorophenyl)borate, and

methylcotadecylsulfonium tetrakis(pentafluorophenyl)borate.

Preferred (L*-H)⁺ cations are methyldioctadecylammonium cations,dimethyloctadecylammonium cations, and ammonium cations derived frommixtures of trialkyl amines containing one or 2 C₁₄₋₁₈ alkyl groups.

Another suitable ion forming, activating cocatalyst comprises a salt ofa cationic oxidizing agent and a noncoordinating, compatible anionrepresented by the formula:(Ox^(h+))_(g)(A^(g−))_(h),wherein:

Ox^(h+) is a cationic oxidizing agent having a charge of h+;

h is an integer from 1 to 3; and

A^(g−) and g are as previously defined.

Examples of cationic oxidizing agents include: ferrocenium,hydrocarbyl-substituted ferrocenium, Ag⁺, or Pb⁺². Preferred embodimentsof A^(g−) are those anions previously defined with respect to theBronsted acid containing activating cocatalysts, especiallytetrakis(pentafluorophenyl)borate.

Another suitable ion forming, activating cocatalyst comprises a compoundwhich is a salt of a carbenium ion and a noncoordinating, compatibleanion represented by the formula:[C]⁺A⁻wherein:

[C]⁺ is a C₁₋₂₀ carbenium ion; and

A⁻ is a noncoordinating, compatible anion having a charge of −1. Apreferred carbenium ion is the trityl cation, that istriphenylmethylium.

A further suitable ion forming, activating cocatalyst comprises acompound which is a salt of a silylium ion and a noncoordinating,compatible anion represented by the formula:(Q¹ ₃Si)⁺A⁻wherein:

Q¹ is C₁₋₁₀ hydrocarbyl, and A⁻ is as previously defined.

Preferred silylium salt activating cocatalysts are trimethylsilyliumtetrakispentafluorophenylborate, triethylsilyliumtetrakispentafluorophenylborate and ether substituted adducts thereof.Silylium salts have been previously generically disclosed in J. ChemSoc. Chem. Comm., 1993, 383-384, as well as Lambert, J. B., et al.,Organometallics, 1994, 13, 2430-2443. The use of the above silyliumsalts as activating cocatalysts for addition polymerization catalysts isdisclosed in U.S. Pat. No. 5,625,087.

Certain complexes of alcohols, mercaptans, silanols, and oximes withtris(pentafluorophenyl)borane are also effective catalyst activators andmay be used according to the present invention. Such cocatalysts aredisclosed in U.S. Pat. No. 5,296,433.

Suitable activating cocatalysts for use herein also include polymeric oroligomeric alumoxanes, especially methylalumoxane (MAO), triisobutylaluminum modified methylalumoxane (MMAO), or isobutylalumoxane; Lewisacid modified alumoxanes, especially perhalogenatedtri(hydrocarbyl)aluminum- or perhalogenated tri(hydrocarbyl)boronmodified alumoxanes, having from 1 to 10 carbons in each hydrocarbyl orhalogenated hydrocarbyl group, and most especiallytris(pentafluorophenyl)borane modified alumoxanes. Such cocatalysts arepreviously disclosed in U.S. Pat. Nos. 6,214,760, 6,160,146, 6,140,521,and 6,696,379.

A class of cocatalysts comprising non-coordinating anions genericallyreferred to as expanded anions, further disclosed in U.S. Pat. No.6,395,671, may be suitably employed to activate the metal complexes ofthe present invention for olefin polymerization. Generally, thesecocatalysts (illustrated by those having imidazolide, substitutedimidazolide, imidazolinide, substituted imidazolinide, benzimidazolide,or substituted benzimidazolide anions) may be depicted as follows:

wherein:

A*⁺ is a cation, especially a proton containing cation, and preferablyis a trihydrocarbyl ammonium cation containing one or two C₁₀₋₄₀ alkylgroups, especially a methyldi (C₁₄₋₂₀ alkyl)ammonium cation,

Q³, independently each occurrence, is hydrogen or a halo, hydrocarbyl,halocarbyl, halohydrocarbyl, silylhydrocarbyl, or silyl, (includingmono-, di- and tri(hydrocarbyl)silyl) group of up to 30 atoms notcounting hydrogen, preferably C₁₋₂₀ alkyl, and

Q² is tris(pentafluorophenyl)borane or tris(pentafluorophenyl)alumane).

Examples of these catalyst activators includetrihydrocarbylammonium-salts, especially, methyldi(C₁₄₋₂₀alkyl)ammonium-salts of:

bis(tris(pentafluorophenyl)borane)imidazolide,bis(tris(pentafluorophenyl)borane)-2-undecylimidazolide,bis(tris(pentafluorophenyl)borane)-2-heptadecylimidazolide,bis(tris(pentafluorophenyl)borane)-4,5-bis(undecyl)imidazolide,bis(tris(pentafluorophenyl)borane)-4,5-bis(heptadecyl)imidazolide,bis(tris(pentafluorophenyl)borane)imidazolinide,bis(tris(pentafluorophenyl)borane)-2-undecylimidazolinide,bis(tris(pentafluorophenyl)borane)-2-heptadecylimidazolinide,bis(tris(pentafluorophenyl)borane)-4,5-bis(undecyl)imidazolinide,bis(tris(pentafluorophenyl)borane)-4,5-bis(heptadecyl)imidazolinide,bis(tris(pentafluorophenyl)borane)-5,6-dimethylbenzimidazolide,bis(tris(pentafluorophenyl)borane)-5,6-bis(undecyl)benzimidazolide,

bis(tris(pentafluorophenyl)alumane)imidazolide,bis(tris(pentafluorophenyl)alumane)-2-undecylimidazolide,bis(tris(pentafluorophenyl)alumane)-2-heptadecylimidazolide,bis(tris(pentafluorophenyl)alumane)-4,5-bis(undecyl)imidazolide,bis(tris(pentafluorophenyl)alumane)-4,5-bis(heptadecyl)imidazolide,bis(tris(pentafluorophenyl)alumane)imidazolinide,bis(tris(pentafluorophenyl)alumane)-2-undecylimidazolinide,bis(tris(pentafluorophenyl)alumane)-2-heptadecylimidazolinide,bis(tris(pentafluorophenyl)alumane)-4,5-bis(undecyl)imidazolinide,bis(tris(pentafluorophonyl)alumane)-4,5-bis(heptadecyl)imidazolinide,bis(tris(pentafluorophenyl)alumane)-5,6-dimethylbenzimidazolide, andbis(tris(pentafluorophenyl)alumane)-5,6-bis(undecyl)benzimidazolide.

Other activators include those described in PCT publication WO 98/07515such as tris(2,2′,2″-nonafluorobiphenyl)fluoroaluminate. Combinations ofactivators are also contemplated by the invention, for example,alumoxanes and ionizing activators in combinations, see for example,EP-A-0 573120, PCT publications WO 94/07928 and WO 95/14044 and U.S.Pat. Nos. 5,153,157 and 5,453,410. WO 98/09996 describes activatingcatalyst compounds with perchlorates, periodates and iodates, includingtheir hydrates. WO 99/18135 describes the use of organoboroaluminumactivators. WO 03/10171 discloses catalyst activators that are adductsof Bronsted acids with Lewis acids. Other activators or methods foractivating a catalyst compound are described in for example, U.S. Pat.Nos. 5,849,852, 5,859,653, 5,869,723, EP-A-615981, and PCT publicationWO 98/32775. All of the foregoing catalyst activators as well as anyother know activator for transition metal complex catalysts may beemployed alone or in combination according to the present invention,however, for best results alumoxane containing cocatalysts are avoided.

The molar ratio of catalyst/cocatalyst employed preferably ranges from1:10,000 to 100:1, more preferably from 1:5000 to 10:1, most preferablyfrom 1:1000 to 1:1. Alumoxane, when used by itself as an activatingcocatalyst, is employed in large quantity, generally at least 100 timesthe quantity of metal complex on a molar basis.Tris(pentafluorophenyl)borane, where used as an activating cocatalyst isemployed in a molar ratio to the metal complex of from 0.5:1 to 10:1,more preferably from 1:1 to 6:1 most preferably from 1:1 to 5:1. Theremaining activating cocatalysts are generally employed in approximatelyequimolar quantity with the metal complex.

During the polymerization, the reaction mixture is contacted with theactivated catalyst composition according to any suitable polymerizationconditions. The process is desirably characterized by use of elevatedtemperatures and pressures. Hydrogen may be employed as a chain transferagent for molecular weight control according to known techniques, ifdesired. As in other similar polymerizations, it is highly desirablethat the monomers and solvents employed be of sufficiently high puritythat catalyst deactivation or premature chain termination does notoccur. Any suitable technique for monomer purification such asdevolatilization at reduced pressure, contacting with molecular sievesor high surface area alumina, or a combination of the foregoingprocesses may be employed.

Supports may be employed in the present invention, especially in slurryor gas-phase polymerizations. Suitable supports include solid,particulated, high surface area, metal oxides, metalloid oxides, ormixtures thereof (interchangeably referred to herein as an inorganicoxide). Examples include: talc, silica, alumina, magnesia, titania,zirconia, Sn₂O₃, aluminosilicates, borosilicates, clays, and mixturesthereof. Suitable supports preferably have a surface area as determinedby nitrogen porosimetry using the B.E.T. method from 10 to 1000 m²/g,and preferably from 100 to 600 m²/g. The average particle size typicallyis from 0.1 to 500 μm, preferably from 1 to 200 μm, more preferably 10to 100 μm.

In one embodiment of the invention the present catalyst composition andoptional support may be spray dried or otherwise recovered in solid,particulated form to provide a composition that is readily transportedand handled. Suitable methods for spray drying a liquid containingslurry are well known in the art and usefully employed herein. Preferredtechniques for spray drying catalyst compositions for use herein aredescribed in U.S. Pat. Nos. 5,648,310 and 5,672,669.

The polymerization is desirably carried out as a continuouspolymerization, preferably a continuous, solution polymerization, inwhich catalyst components, monomers, and optionally solvent, adjuvants,scavengers, and polymerization aids are continuously supplied to one ormore reactors or zones and polymer product continuously removed therefrom. Within the scope of the terms “continuous” and “continuously” asused in this context are those processes in which there are intermittentadditions of reactants and removal of products at small regular orirregular intervals, so that, over time, the overall process issubstantially continuous. While the multi-centered shuttling agent andthe chain shuttling agent(s) (if used) may be added at any point duringthe polymerization including in the first reactor or zone, at the exitor slightly before the exit of the first reactor, between the firstreactor or zone and any subsequent reactor or zone, or even solely tothe second reactor or zone, if present, both are preferably added at theinitial stages of the polymerization. If there exists any difference inmonomers, temperatures, pressures or other polymerization conditionwithin a reactor or between two or more reactors or zones connected inseries, polymer segments of differing composition such as comonomercontent, crystallinity, density, tacticity, regio-regularity, or otherchemical or physical difference, within the same molecule are formed inthe polymers of the invention. In such event, the size of each segmentor block is determined by the polymer reaction conditions, andpreferably is a most probable distribution of polymer sizes.

If multiple reactors are employed, each can be independently operatedunder high pressure, solution, slurry, or gas phase polymerizationconditions. In a multiple zone polymerization, all zones operate underthe same type of polymerization, such as solution, slurry, or gas phase,but, optionally, at different process conditions. For a solutionpolymerization process, it is desirable to employ homogeneousdispersions of the catalyst components in a liquid diluent in which thepolymer is soluble under the polymerization conditions employed. Onesuch process utilizing an extremely fine silica or similar dispersingagent to produce such a homogeneous catalyst dispersion wherein normallyeither the metal complex or the cocatalyst is only poorly soluble isdisclosed in U.S. Pat. No. 5,783,512. A high pressure process is usuallycarried out at temperatures from 100° C. to 400° C. and at pressuresabove 500 bar (50 MPa). A slurry process typically uses an inerthydrocarbon diluent and temperatures of from 0° C. up to a temperaturejust below the temperature at which the resulting polymer becomessubstantially soluble in the inert polymerization medium. Preferredtemperatures in a slurry polymerization are from 30° C., preferably from60° C. up to 115° C., preferably up to 100° C., depending on the polymerbeing prepared. Pressures typically range from atmospheric (100 kPa) to500 psi (3.4 MPa).

In all of the foregoing processes, continuous or substantiallycontinuous polymerization conditions are preferably employed. The use ofsuch polymerization conditions, especially continuous, solutionpolymerization processes, allows the use of elevated reactortemperatures which results in the economical production of the presentblock copolymers in high yields and efficiencies.

The catalyst may be prepared as a homogeneous composition by addition ofthe requisite metal complex or multiple complexes to a solvent in whichthe polymerization will be conducted or in a diluent compatible with theultimate reaction mixture. The desired cocatalyst or activator and,optionally, a shuttling agent may be combined with the catalystcomposition either prior to, simultaneously with, or after combinationof the catalyst with the monomers to be polymerized and any additionalreaction diluent. Desirably, the MSA is added at the same time.

At all times, the individual ingredients as well as any active catalystcomposition must be protected from oxygen, moisture and other catalystpoisons. Therefore, the catalyst components, multi-centered shuttlingagent and activated catalysts must be prepared and stored in an oxygenand moisture free atmosphere, preferably under a dry, inert gas such asnitrogen.

Without limiting in any way the scope of the invention, one means forcarrying out such a polymerization process is as follows. In one or morewell stirred tank or loop reactors operating under solutionpolymerization conditions, the monomers to be polymerized are introducedcontinuously together with any solvent or diluent at one part of thereactor. The reactor contains a relatively homogeneous liquid phasecomposed substantially of monomers together with any solvent or diluentand dissolved polymer. Preferred solvents include C₄₋₁₀ hydrocarbons ormixtures thereof, especially alkanes such as hexane or mixtures ofalkanes, as well as one or more of the monomers employed in thepolymerization. Examples of suitable loop reactors and a variety ofsuitable operating conditions for use therewith, including the use ofmultiple loop reactors, operating in series, are found in U.S. Pat. Nos.5,977,251, 6,319,989 and 6,683,149.

Catalyst along with cocatalyst and multi-centered shuttling agent arecontinuously or intermittently introduced in the reactor liquid phase orany recycled portion thereof at a minimum of one location. The reactortemperature and pressure may be controlled by adjusting thesolvent/monomer ratio, the catalyst addition rate, as well as by use ofcooling or heating coils, jackets or both. The polymerization rate iscontrolled by the rate of catalyst addition. The content of a givenmonomer in the polymer product is influenced by the ratio of monomers inthe reactor, which is controlled by manipulating the respective feedrates of these components to the reactor. The polymer product molecularweight is controlled, optionally, by controlling other polymerizationvariables such as the temperature, monomer concentration, or by thepreviously mentioned multi-centered shuttling agent, or a chainterminating agent such as hydrogen, as is well known in the art.

In one embodiment of the invention, a second reactor is connected to thedischarge of the reactor, optionally by means of a conduit or othertransfer means, such that the reaction mixture prepared in the firstreactor is discharged to the second reactor without substantiallytermination of polymer growth. Between the first and second reactors, adifferential in at least one process condition may be established.Preferably for use in formation of a copolymer of two or more monomers,the difference is the presence or absence of one or more comonomers or adifference in comonomer concentration. Additional reactors, eacharranged in a manner similar to the second reactor in the series may beprovided as well. Further polymerization is ended by contacting thereactor effluent with a catalyst kill agent such as water, steam or analcohol or with a coupling agent if a coupled reaction product isdesired.

The resulting polymer product is recovered by flashing off volatilecomponents of the reaction mixture such as residual monomer(s) ordiluent at reduced pressure, and, if necessary, conducting furtherdevolatilization in equipment such as a devolatilizing extruder. In acontinuous process the mean residence time of the catalyst and polymerin the reactor generally is from 5 minutes to 8 hours, and preferablyfrom 10 minutes to 6 hours.

Alternatively, the foregoing polymerization may be carried out in a plugflow reactor optionally with a monomer, catalyst, multi-centeredshuttling agent, temperature or other gradient established betweendiffering zones or regions thereof, further optionally accompanied byseparate addition of catalysts and/or chain shuttling agent, andoperating under adiabatic or non-adiabatic polymerization conditions.

The catalyst composition may also be prepared and employed as aheterogeneous catalyst by adsorbing the requisite components on an inertinorganic or organic particulated solid, as previously disclosed. In apreferred embodiment, a heterogeneous catalyst is prepared byco-precipitating the metal complex and the reaction product of an inertinorganic compound and an active hydrogen containing activator,especially the reaction product of a tri(C₁₋₄ alkyl) aluminum compoundand an ammonium salt of a hydroxyaryltris(pentafluorophenyl)borate, suchas an ammonium salt of(4-hydroxy-3,5-ditertiarybutylphenyl)tris(pentafluorophenyl)borate. Whenprepared in heterogeneous or supported form, the catalyst compositionmay be employed in a slurry or a gas phase polymerization. As apractical limitation, slurry polymerization takes place in liquiddiluents in which the polymer product is substantially insoluble.Preferably, the diluent for slurry polymerization is one or morehydrocarbons with less than 5 carbon atoms. If desired, saturatedhydrocarbons such as ethane, propane or butane may be used in whole orpart as the diluent. As with a solution polymerization, the α-olefincomonomer or a mixture of different α-olefin monomers may be used inwhole or part as the diluent. Most preferably at least a major part ofthe diluent comprises the α-olefin monomer or monomers to bepolymerized.

Preferably for use in gas phase polymerization processes, the supportmaterial and resulting catalyst has a median particle diameter from 20to 200 μm, more preferably from 30 μm to 150 μm, and most preferablyfrom 50 μm to 100 μm. Preferably for use in slurry polymerizationprocesses, the support has a median particle diameter from 1 μm to 200μm, more preferably from 5 μm to 100 μm, and most preferably from 10 μmto 80 μm.

Suitable gas phase polymerization process for use herein aresubstantially similar to known processes used commercially on a largescale for the manufacture of polypropylene, ethylene/α-olefincopolymers, and other olefin polymers. The gas phase process employedcan be, for example, of the type which employs a mechanically stirredbed or a gas fluidized bed as the polymerization reaction zone.Preferred is the process wherein the polymerization reaction is carriedout in a vertical cylindrical polymerization reactor containing afluidized bed of polymer particles supported or suspended above aperforated plate or fluidization grid, by a flow of fluidization gas.

The gas employed to fluidize the bed comprises the monomer or monomersto be polymerized, and also serves as a heat exchange medium to removethe heat of reaction from the bed. The hot gases emerge from the top ofthe reactor, normally via a tranquilization zone, also known as avelocity reduction zone, having a wider diameter than the fluidized bedand wherein fine particles entrained in the gas stream have anopportunity to gravitate back into the bed. It can also be advantageousto use a cyclone to remove ultra-fine particles from the hot gas stream.The gas is then normally recycled to the bed by means of a blower orcompressor and one or more heat exchangers to strip the gas of the heatof polymerization.

A preferred method of cooling of the bed, in addition to the coolingprovided by the cooled recycle gas, is to feed a volatile liquid to thebed to provide an evaporative cooling effect, often referred to asoperation in the condensing mode. The volatile liquid employed in thiscase can be, for example, a volatile inert liquid, for example, asaturated hydrocarbon having 3 to 8, preferably 4 to 6, carbon atoms. Inthe case that the monomer or comonomer itself is a volatile liquid, orcan be condensed to provide such a liquid, this can suitably be fed tothe bed to provide an evaporative cooling effect. The volatile liquidevaporates in the hot fluidized bed to form gas which mixes with thefluidizing gas. If the volatile liquid is a monomer or comonomer, itwill undergo some polymerization in the bed. The evaporated liquid thenemerges from the reactor as part of the hot recycle gas, and enters thecompression/heat exchange part of the recycle loop. The recycle gas iscooled in the heat exchanger and, if the temperature to which the gas iscooled is below the dew point, liquid will precipitate from the gas.This liquid is desirably recycled continuously to the fluidized bed. Itis possible to recycle the precipitated liquid to the bed as liquiddroplets carried in the recycle gas stream. This type of process isdescribed, for example in EP-89691; U.S. Pat. No. 4,543,399; WO-94/25495and U.S. Pat. No. 5,352,749. A particularly preferred method ofrecycling the liquid to the bed is to separate the liquid from therecycle gas stream and to reinject this liquid directly into the bed,preferably using a method which generates fine droplets of the liquidwithin the bed. This type of process is described in WO-94/28032.

The polymerization reaction occurring in the gas fluidized bed iscatalyzed by the continuous or semi-continuous addition of catalystcomposition as previously disclosed. The catalyst composition may besubjected to a prepolymerization step, for example, by polymerizing asmall quantity of olefin monomer in a liquid inert diluent, to provide acatalyst composite comprising supported catalyst particles embedded inolefin polymer particles as well.

The polymer is produced directly in the fluidized bed by polymerizationof the monomer or mixture of monomers on the fluidized particles ofcatalyst composition, supported catalyst composition or prepolymerizedcatalyst composition within the bed. Start-up of the polymerizationreaction is achieved using a bed of preformed polymer particles, whichare preferably similar to the desired polymer, and conditioning the bedby drying with inert gas or nitrogen prior to introducing the catalystcomposition, the monomers and any other gases which it is desired tohave in the recycle gas stream, such as a diluent gas, hydrogen chaintransfer agent, or an inert condensable gas when operating in gas phasecondensing mode. The produced polymer is discharged continuously orsemi-continuously from the fluidized bed as desired.

The gas phase processes most suitable for the practice of this inventionare continuous processes which provide for the continuous supply ofreactants to the reaction zone of the reactor and the removal ofproducts from the reaction zone of the reactor, thereby providing asteady-state environment on the macro scale in the reaction zone of thereactor. Products are readily recovered by exposure to reduced pressureand optionally elevated temperatures (devolatilization) according toknown techniques. Typically, the fluidized bed of the gas phase processis operated at temperatures greater than 50° C., preferably from 60° C.to 110° C., more preferably from 70° C. to 110° C.

Suitable gas phase processes which are adaptable for use in the processof this invention are disclosed in U.S. Pat. Nos. 4,588,790; 4,543,399;5,352,749; 5,436,304; 5,405,922; 5,462,999; 5,461,123; 5,453,471;5,032,562; 5,028,670; 5,473,028; 5,106,804; 5,556,238; 5,541,270;5,608,019; and 5,616,661.

As previously mentioned, functionalized derivatives of polymers are alsoincluded within the present invention. Examples include metallatedpolymers wherein the metal is the remnant of the catalyst or chainshuttling agent employed, as well as further derivatives thereof.Because a substantial fraction of the polymeric product exiting thereactor is terminated with the multi-centered shuttling agent, furtherfunctionalization is relatively easy. The metallated polymer species canbe utilized in well known chemical reactions such as those suitable forother alkyl-aluminum, alkyl-gallium, alkyl-zinc, or alkyl-Group 1compounds to form amine-, hydroxy-, epoxy-, silane, vinylic, and otherfunctionalized terminated polymer products. Examples of suitablereaction techniques that are adaptable for use here in are described inNegishi, “Organometallics in Organic Synthesis”, Vol. 1 and 2, (1980),and other standard texts in organometallic and organic synthesis.

Polymer Products

Utilizing the present process, novel polymer compositions, includingpseudo-block copolymers of one or more olefin monomers having thepresent bimodal molecular weight distribution, are readily prepared.Preferred polymers comprise in polymerized form at least one monomerselected from the group consisting of ethylene, propylene and4-methyl-1-pentene. Highly desirably, the polymers are interpolymerscomprising in polymerized form ethylene, propylene or 4-methyl-1-penteneand at least one different C₂₋₂₀ α-olefin comonomer, and optionally oneor more additional copolymerizable comonomers. Suitable comonomers areselected from diolefins, cyclic olefins, and cyclic diolefins,halogenated vinyl compounds, and vinylidene aromatic compounds.Preferred polymers are interpolymers of ethylene with 1-butene, 1-hexeneor 1-octene. Desirably, the polymer compositions of the invention havean ethylene content from 1 to 99 percent, a diene content from 0 to 10percent, and a styrene and/or C₃₋₈-olefin content from 99 to 1 percent,based on the total weight of the polymer. Further preferably, thepolymers of the invention have a weight average molecular weight (Mw)from 10,000 to 2,500,000.

The polymers of the invention can have a melt index, I₂, from 0.01 to2000 g/10 minutes, preferably from 0.01 to 1000 g/10 minutes, morepreferably from 0.01 to 500 g/10 minutes, and especially from 0.01 to100 g/10 minutes. Desirably, the invented polymers can have molecularweights, M_(w), from 1,000 g/mole to 5,000,000 g/mole, preferably from1000 g/mole to 1,000,000, more preferably from 1000 g/mole to 500,000g/mole, and especially from 1,000 g/mole to 300,000 g/mole. The densityof the invented polymers can be from 0.80 to 0.99 g/cm³ and preferably,for ethylene containing polymers, from 0.85 g/cm³ to 0.97 g/cm³.

The polymers of the invention may be differentiated from conventional,random copolymers, physical blends of polymers, and block copolymersprepared via sequential monomer addition, fluxional catalysts, or byanionic or cationic living polymerization techniques, due to thepreviously mentioned unique molecular weight distribution. If present,the separate regions or blocks within each polymer are relativelyuniform, depending on the uniformity of reactor conditions, andchemically distinct from each other. That is, the comonomerdistribution, tacticity, or other property of segments within thepolymer are relatively uniform within the same block or segment.However, the average block length is not a narrow distribution, butdesirably is a most probable distribution. Such polymer products havingtwo or more blocks or segments and a broader size distribution than aconventional block copolymer prepared by anionic techniques, arereferred to herein as pseudo-block copolymers. The polymers haveproperties approximating in many respects, those of pure blockcopolymers, and in some aspects exceeding the properties of pure blockcopolymers.

Various additives may be usefully incorporated into the presentcompositions in amounts that do not detract from the properties of theresultant composition. These additives include reinforcing agents,fillers including conductive and non-conductive materials, ignitionresistant additives, antioxidants, heat and light stabilizers,colorants, extenders, crosslinkers, blowing agents, plasticizers, flameretardants, anti-drip agents, lubricants, slip additives, anti-blockingaids, antidegradants, softeners, waxes, and pigments.

Applications and End Uses

The polymer composition of the invention can be employed in a variety ofconventional thermoplastic fabrication processes to produce usefularticles, including objects comprising at least one film layer, such asa monolayer film, or at least one layer in a multilayer film, preparedby cast, blown, calendered, or extrusion coating processes; moldedarticles, such as blow molded, injection molded, or rotomolded articles;extrusions; fibers; and woven or non-woven fabrics. Thermoplasticcompositions comprising the present polymers, include blends with othernatural or synthetic polymers and additives, including the previouslymentioned reinforcing agents, fillers, ignition resistant additives,antioxidants, heat and light stabilizers, colorants, extenders,crosslinkers, blowing agents, plasticizers, flame retardants, anti-dripagents, lubricants, slip additives, anti-blocking aids, antidegradants,softeners, waxes, and pigments.

Fibers that may be prepared from the present polymers or blends includestaple fibers, tow, multicomponent, sheath/core, twisted, andmonofilament. Suitable fiber forming processes include spinbonded, meltblown techniques, as disclosed in U.S. Pat. Nos. 4,430,563, 4,663,220,4,668,566, and 4,322,027, gel spun fibers as disclosed in U.S. Pat. No.4,413,110, woven and nonwoven fabrics, as disclosed in U.S. Pat. No.3,485,706, or structures made from such fibers, including blends withother fibers, such as polyester, nylon or cotton, thermoformed articles,extruded shapes, including profile extrusions and co-extrusions,calendared articles, and drawn, twisted, or crimped yarns or fibers. Thenew polymers described herein are also useful for wire and cable coatingoperations, as well as in sheet extrusion for vacuum forming operations,and forming molded articles, including the use of injection molding,blow molding process, or rotomolding processes. Compositions comprisingthe olefin polymers can also be formed into fabricated articles such asthose previously mentioned using conventional polyolefin processingtechniques which are well known to those skilled in the art ofpolyolefin processing.

Dispersions (both aqueous and non-aqueous) can also be formed using thepresent polymers or formulations comprising the same. Frothed foamscomprising the invented polymers can also be formed, using for examplethe process disclosed in WO04/021622. The polymers may also becrosslinked by any known means, such as the use of peroxide, electronbeam, silane, azide, or other cross-linking technique. The polymers canalso be chemically modified, such as by grafting (for example by use ofmaleic anhydride (MAH), silanes, or other grafting agent), halogenation,amination, sulfonation, or other chemical modification.

Suitable polymers for blending with the polymers of the inventioninclude thermoplastic and non-thermoplastic polymers including naturaland synthetic polymers. Exemplary polymers for blending includepolypropylene, (both impact modifying polypropylene, isotacticpolypropylene, atactic polypropylene, and random ethylene/propylenecopolymers), various types of polyethylene, including high pressure,free-radical LDPE, Ziegler Natta LLDPE, metallocene PE, includingmultiple reactor PE (“in reactor” blends of Ziegler-Natta PE andmetallocene PE, such as products disclosed in U.S. Pat. Nos. 6,545,088,6,538,070, 6,566,446, 5,844,045, 5,869,575, and 6,448,341,ethylene-vinyl acetate (EVA), ethylene/vinyl alcohol copolymers,polystyrene, impact modified polystyrene, ABS, styrene/butadiene blockcopolymers and hydrogenated derivatives thereof (SBS and SEBS), andthermoplastic polyurethanes. Homogeneous polymers such as olefinplastomers and elastomers, ethylene and propylene-based copolymers (forexample polymers available under the trade designation VERSIFY™available from The Dow Chemical Company and VISTAMAXX™ available fromExxonMobil can also be useful as components in blends comprising thepresent polymer composition.

The blends may be prepared by mixing or kneading the respectivecomponents at a temperature around or above the melt point temperatureof one or both of the components. For most of the present compositions,this temperature may be above 130° C., 145° C., or even above 150° C.Typical polymer mixing or kneading equipment that is capable of reachingthe desired temperatures and melt plastifying the mixture may beemployed. These include mills, kneaders, extruders (both single screwand twin-screw), Banbury mixers, and calendars. The sequence of mixingand method may depend on the final composition. A combination of Banburybatch mixers and continuous mixers may also be employed, such as aBanbury mixer followed by a mill mixer followed by an extruder.

The blend compositions may contain processing oils, plasticizers, andprocessing aids. Rubber processing oils have a certain ASTM designationsand paraffinic, napthenic or aromatic process oils are all suitable foruse. Generally from 0 to 150 parts, more preferably 0 to 100 parts, andmost preferably from 0 to 50 parts of oil per 100 parts of total polymercomposition are employed. Higher amounts of oil may tend to improve theprocessing of the resulting product at the expense of some physicalproperties. Additional processing aids include conventional waxes, fattyacid salts, such as calcium stearate or zinc stearate, (poly)alcoholsincluding glycols, (poly)alcohol ethers, including glycol ethers,(poly)esters, including (poly)glycol esters, and metal salt-, especiallyGroup 1 or 2 metal or zinc-, salt derivatives thereof.

Compositions according to the invention may also contain anti-ozonantsand anti-oxidants that are known to a person of ordinary skill. Theanti-ozonants may be physical protectants such as waxy materials thatcome to the surface and protect the part from oxygen or ozone or theymay be chemical protectors that react with oxygen or ozone. Suitablechemical protectors include styrenated phenols, butylated octylatedphenol, butylated di(dimethylbenzyl)phenol, p-phenylenediamines,butylated reaction products of p-cresol and dicyclopentadiene (DCPD),polyphenolic anitioxidants, hydroquinone derivatives, quinoline,diphenylene antioxidants, thioester antioxidants, and blends thereof.Some representative trade names of such products are Wingstay™ Santioxidant, Polystay™ 100 antioxidant, Polystay™ 100 AZ antioxidant,Polystay™ 200 antioxidant, Wingstay™ L antioxidant, Wingstay™ LBLSantioxidant, Wingstay™ K antioxidant, Wingstay™ 29 antioxidant,Wingstay™ SN-1 antioxidant, and Irganox™ antioxidants. In someapplications, the antioxidants and antiozonants used will preferably benon-staining and non-migratory.

For providing additional stability against UV radiation, hindered aminelight stabilizers (HALS) and UV absorbers may be also used. Suitableexamples include Tinuvin™ 123, Tinuvin™ 144, Tinuvin™ 622, Tinuvin™ 765,Tinuvin™ 770, and Tinuvin™ 780, available from Ciba Specialty Chemicals,and Chemisorb™ T944, available from Cytex Plastics, Houston, Tex., USA.A Lewis acid may be additionally included with a HALS compound in orderto achieve superior surface quality, as disclosed in U.S. Pat. No.6,051,681.

For some compositions, additional mixing process may be employed topre-disperse the anti-oxidants, anti-ozonants, pigment, UV absorbers,and/or light stabilizers to form a masterbatch, and subsequently to formpolymer blends therefrom.

Certain compositions according to the invention, especially thosecontaining the remnant of a conjugated diene comonomer, may besubsequently crosslinked to form cured compositions. Suitablecrosslinking agents (also referred to as curing or vulcanizing agents)for use herein include sulfur based, peroxide based, or phenolic basedcompounds. Examples of the foregoing materials are found in the art,including in U.S. Pat. Nos. 3,758,643, 3,806,558, 5,051,478, 4,104,210,4,130,535, 4,202,801, 4,271,049, 4,340,684, 4,250,273, 4,927,882,4,311,628 and 5,248,729.

When sulfur based curing agents are employed, accelerators and cureactivators may be used as well. Accelerators are used to control thetime and/or temperature required for dynamic vulcanization and toimprove the properties of the resulting cross-linked article. In oneembodiment, a single accelerator or primary accelerator is used. Theprimary accelerator(s) may be used in total amounts ranging from 0.5 to4, preferably 0.8 to 1.5, phr, based on total composition weight. Inanother embodiment, combinations of a primary and a secondaryaccelerator might be used with the secondary accelerator being used insmaller amounts, such as from 0.05 to 3 phr, in order to activate and toimprove the properties of the cured article. Combinations ofaccelerators generally produce articles having properties that aresomewhat better than those produced by use of a single accelerator. Inaddition, delayed action accelerators may be used which are not affectedby normal processing temperatures yet produce a satisfactory cure atordinary vulcanization temperatures. Vulcanization retarders might alsobe used. Suitable types of accelerators that may be used in the presentinvention are amines, disulfides, guanidines, thioureas, thiazoles,thiurams, sulfenamides, dithiocarbamates and xanthates. Preferably, theprimary accelerator is a sulfenamide. If a second accelerator is used,the secondary accelerator is preferably a guanidine, dithiocarbamate orthiuram compound. Certain processing aids and cure activators such asstearic acid and ZnO may also be used. When peroxide based curing agentsare used, co-activators or coagents may be used in combinationtherewith. Suitable coagents include trimethylolpropane triacrylate(TMPTA), trimethylolpropane trimethacrylate (TMPTMA), triallyl cyanurate(TAC), triallyl isocyanurate (TAIC), among others. Use of peroxidecrosslinkers and optional coagents used for partial or complete dynamicvulcanization are known in the art and disclosed for example in thepublication, “Peroxide Vulcanization of Elastomers”, Vol. 74, No 3,July-August 2001.

The degree of crosslinking in a cured composition according to theinvention may be measured by dissolving the composition in a solvent fora specified duration, and calculating the percent gel or unextractablerubber. The percent gel normally increases with increasing crosslinkinglevels. For cured articles according to the invention, the percent gelcontent is desirably in the range from 5 to 100 percent.

The present compositions and blends thereof uniquely possess improvedmelt strength properties due to the presence of the high molecularweight component and unique molecular weight distribution, therebyallowing the present compositions and blends thereof to be usefullyemployed in foam and in thermoforming applications where high meltstrength is desired.

Thermoplastic compositions according to the invention may also containorganic or inorganic fillers or other additives such as starch, talc,calcium carbonate, glass fibers, polymeric fibers (including nylon,rayon, cotton, polyester, and polyaramide), metal fibers, wire, mesh,flakes or particles, expandable layered silicates, phosphates orcarbonates, such as clays, mica, silica, alumina, aluminosilicates oraluminophosphates, carbon whiskers, carbon fibers, nanoparticlesincluding nanotubes and nonofibers, wollastonite, graphite, zeolites,and ceramics, such as silicon carbide, silicon nitride or titanias.Silane based oils or other coupling agents may also be employed forbetter filler bonding. Additional suitable additives include tackifiers;oils, including paraffinic or napthelenic oils; and other natural andsynthetic polymers, including other polymers according to the invention.

The polymer compositions of this invention, including the foregoingblends, may be processed by conventional molding techniques such asinjection molding, extrusion molding, thermoforming, slush molding, overmolding, insert molding, blow molding, and other techniques. Films,including multi-layer films, may be produced by cast or tenteringprocesses, including blown film processes.

Testing Methods

In the foregoing characterizing disclosure and the examples that follow,the following analytical techniques may be employed:

Molecular Weight Determination

Molecular weights are determined by optical analysis techniquesincluding deconvoluted gel permeation chromatography coupled with a lowangle laser light scattering detector (GPC-LALLS) as described by Rudin,A., “Modern Methods of Polymer Characterization”, John Wiley & Sons, NewYork (1991) pp. 103-112.

Standard CRYSTAF Method

Branching distributions are determined by crystallization analysisfractionation (CRYSTAF) using a CRYSTAF 200 unit commercially availablefrom PolymerChar, Valencia, Spain. The samples are dissolved in 1,2,4trichlorobenzene at 160° C. (0.66 mg/mL) for 1 hr and stabilized at 95°C. for 45 minutes. The sampling temperatures range from 95 to 30° C. ata cooling rate of 0.2° C./min. An infrared detector is used to measurethe polymer solution concentrations. The cumulative solubleconcentration is measured as the polymer crystallizes while thetemperature is decreased. The analytical derivative of the cumulativeprofile reflects the short chain branching distribution of the polymer.

The CRYSTAF peak temperature and area are identified by the peakanalysis module included in the CRYSTAF Software (Version 2001.b,PolymerChar, Valencia, Spain). The CRYSTAF peak finding routineidentifies a peak temperature as a maximum in the dW/dT and the areabetween the largest positive inflections on either side of theidentified peak in the derivative curve.

DSC Standard Method

Differential Scanning Calorimetry results are determined using a TAImodel Q1000 DSC equipped with an RCS cooling accessory and anautosampler. A nitrogen purge gas flow of 50 ml/min is used. The sampleis pressed into a thin film and melted in the press at 175° C. and thenair-cooled to room temperature (25° C.). About 10 mg of material in theform of a 5-6 mm diameter disk is accurately weighed and placed in analuminum foil pan (ca 50 mg) which is then crimped shut. The thermalbehavior of the sample is investigated with the following temperatureprofile. The sample is rapidly heated to 180° C. and held isothermal for3 minutes in order to remove any previous thermal history. The sample isthen cooled to −40° C. at 10° C./min cooling rate and held at −40° C.for 3 minutes. The sample is then heated to 150° C. at 10° C./min.heating rate. The cooling and second heating curves are recorded.

The DSC melting peak is measured as the maximum in heat flow rate (W/g)with respect to the linear baseline drawn between −30° C. and end ofmelting. The heat of fusion is measured as the area under the meltingcurve between −30° C. and the end of melting using a linear baseline.

Abrasion Resistance

Abrasion resistance is measured on compression molded plaques accordingto ISO 4649. The average value of 3 measurements is reported. Plaques of6.4 mm thick are compression molded using a hot press (Carver Model#4095-4PR1001R). The pellets are placed between polytetrafluoroethylenesheets, heated at 190° C. at 55 psi (380 kPa) for 3 min, followed by 1.3MPa for 3 min, and then 2.6 MPa for 3 min. Next the film is cooled inthe press with running cold water at 1.3 MPa for 1 min.

GPC Method

The gel permeation chromatographic system consists of either a PolymerLaboratories Model PL-210 or a Polymer Laboratories Model PL-220instrument. The column and carousel compartments are operated at 140° C.Three Polymer Laboratories 10-micron Mixed-B columns are used. Thesolvent is 1,2,4 trichlorobenzene. The samples are prepared at aconcentration of 0.1 grams of polymer in 50 milliliters of solventcontaining 200 ppm of butylated hydroxytoluene (BHT). Samples areprepared by agitating lightly for 2 hours at 160° C. The injectionvolume used is 100 microliters and the flow rate is 1.0 ml/minute.

Calibration of the GPC column set is performed with 21 narrow molecularweight distribution polystyrene standards with molecular weights rangingfrom 580 to 8,400,000, arranged in 6 “cocktail” mixtures with at least adecade of separation between individual molecular weights. The standardsare purchased from Polymer Laboratories (Shropshire, UK). Thepolystyrene standards are prepared at 0.025 grams in 50 milliliters ofsolvent for molecular weights equal to or greater than 1,000,000 and0.05 grams in 50 milliliters of solvent for molecular weights less than1,000,000. The polystyrene standards are dissolved at 80° C. with gentleagitation for 30 minutes. The narrow standards mixtures are run firstand in order of decreasing highest molecular weight component tominimize degradation. The polystyrene standard peak molecular weightsare converted to polyethylene molecular weights using the followingequation (as described in Williams and Ward, J. Polym. Sci., Polym.Let., 6, 621 (1968)): M_(polyethylene)=0.431(M_(polystrene)).

Polyetheylene equivalent molecular weight calculations are performedusing Viscotek TriSEC software Version 3.0.

Compression Set

Compression set is measured according to ASTM D 395. The sample isprepared by stacking 25.4 mm diameter round discs of 3.2 mm, 2.0 mm, and0.25 mm thickness until a total thickness of 12.7 mm is reached. Thediscs are cut from 12.7 cm×12.7 cm compression molded plaques moldedwith a hot press under the following conditions: zero pressure for 3 minat 190° C., followed by 86 MPa for 2 min at 190° C., followed by coolinginside the press with cold running water at 86 MPa.

Density

Density measurement are conducted according to ASTM D 1928. Measurementsare made within one hour of sample pressing using ASTM D792, Method B.

Flexural/Secant Modulus

Samples are compression molded using ASTM D 1928. Flexural and 2 percentsecant moduli are measured according to ASTM D-790.

Optical Properties, Tensile, Hysteresis, and Tear

Films of 0.4 mm thickness are compression molded using a hot press(Carver Model #4095-4PR1001R). The pellets are placed betweenpolytetrafluoroethylene sheets, heated at 190° C. at 55 psi (380 kPa)for 3 min, followed by 1.3 MPa for 3 min, and then 2.6 MPa for 3 min.The film is then cooled in the press with running cold water at 1.3 MPafor 1 min. The compression molded films are used for opticalmeasurements, tensile behavior, recovery, and stress relaxation.

Clarity is measured using BYK Gardner Haze-gard as specified in ASTM D1746.

45° gloss is measured using BYK Gardner Glossmeter Microgloss 45° asspecified in ASTM D-2457

Internal haze is measured using BYK Gardner Haze-gard based on ASTM D1003 Procedure A. Mineral oil is applied to the film surface to removesurface scratches.

Stress-strain behavior in uniaxial tension is measured using ASTM D 1708microtensile specimens. Samples are stretched with an Instron at 500percent (%) min⁻¹ at 21° C. Tensile strength and elongation at break arereported from an average of 5 specimens.

100% and 300% Hysteresis is determined from cyclic loading to 100% and300% strains according to ASTM D 1708 with an Instron™ instrument. Thesample is loaded and unloaded at 267% min⁻¹ for 3 cycles at 21° C.Cyclic experiments at 300% and 80° C. are conducted using anenvironmental chamber. In the 80° C. experiment, the sample is allowedto equilibrate for 45 minutes at the test temperature before testing. Inthe 21° C., 300% strain cyclic experiment, the retractive stress at 150%strain from the first unloading cycle is recorded. Percent recovery forall experiments are calculated from the first unloading cycle using thestrain at which the load returned to the base line. The percent recoveryis defined as:

${\%\mspace{14mu}{Recovery}} = {\frac{ɛ_{f} - ɛ_{s}}{ɛ_{f}} \times 100}$

where ε_(f) is the strain taken for cyclic loading and ε_(s) is thestrain where the load returns to the baseline during the 1^(st)unloading cycle.

Stress relaxation is measured at 50 percent strain and 37° C. for 12hours using an Instron instrument equipped with an environmentalchamber. The gauge geometry was 76 mm×25 mm×0.4 mm. After equilibratingat 37° C. for 45 min in the environmental chamber, the sample wasstretched to 50% strain at 333% min⁻¹. Stress was recorded as a functionof time for 12 hours. The percent stress relaxation after 12 hours wascalculated using the formula:

${\%\mspace{14mu}{Stress}\mspace{14mu}{Relaxation}} = {\frac{L_{0} - L_{12}}{L_{0}} \times 100}$where L₀ is the load at 50% strain at 0 time and L₁₂ is the load at 50percent strain after 12 hours.

Tensile notched tear experiments are carried out on samples having adensity of 0.88 g/cc or less using an Instron™ instrument. The geometryconsists of a gauge section of 76 mm×13 mm×0.4 min with a 2 mm notch cutinto the sample at half the specimen length. The sample is stretched at508 mm min⁻¹ at 21° C. until it breaks. The tear energy is calculated asthe area under the stress-elongation curve up to strain at maximum load.An average of at least 3 specimens are reported.

TMA

Thermal Mechanical Analysis is conducted on 30 mm diameter×3.3 mm thick,compression molded discs, formed at 180° C. and 10 MPa molding pressurefor 5 minutes and then air quenched. The instrument used is a TMA 7,brand available from Perkin-Elmer. In the test, a probe with 1.5 mmradius tip (P/N N519-0416) is applied to the surface of the sample discwith 1N force. The temperature is raised at 5° C./min from 25° C. Theprobe penetration distance is measured as a function of temperature. Theexperiment ends when the probe has penetrated 1 mm into the sample.

DMA

Dynamic Mechanical Analysis (DMA) is measured on compression moldeddisks formed in a hot press at 180° C. at 10 MPa pressure for 5 minutesand then water cooled in the press at 90° C./min. Testing is conductedusing an ARES controlled strain rheometer (TA instruments) equipped withdual cantilever fixtures for torsion testing.

A 1.5 mm plaque is pressed and cut in a bar of dimensions 32×12 mm. Thesample is clamped at both ends between fixtures separated by 10 min(grip separation ΔL) and subjected to successive temperature steps from−100° C. to 200° C. (5° C. per step). At each temperature the torsionmodulus G′ is measured at an angular frequency of 10 rad/s, the strainamplitude being maintained between 0.1 percent and 4 percent to ensurethat the torque is sufficient and that the measurement remains in thelinear regime.

An initial static force of 10 g is maintained (auto-tension mode) toprevent slack in the sample when thermal expansion occurs. As aconsequence, the grip separation ΔL increases with the temperature,particularly above the melting or softening point of the polymer sample.The test stops at the maximum temperature or when the gap between thefixtures reaches 65 mm.

Pellet Blocking Behavior

Pellets (150 g) are loaded into a 2 inch (5 cm) diameter hollow cylinderthat is made of two halves held together by a hose clamp. A 2.75 lb(1.25 kg) load is applied to the pellets in the cylinder at 45° C. for 3days. After 3 days, the pellets loosely consolidate into a cylindricalshaped plug. The plug is removed from the form and the pellet blockingforce measured by loading the cylinder of blocked pellets in compressionusing an Instron™ instrument to measure the compressive force needed tobreak the cylinder into pellets.

Melt Properties

Melt Flow Rate (MFR) and Melt index, or I₂, are measured in accordancewith ASTM D1238, Condition 190° C./2.16 kg.

ATREF

Analytical temperature rising elution fractionation (ATREF) analysis isconducted according to the method described in U.S. Pat. No. 4,798,081.The composition to be analyzed is dissolved in trichlorobenzene andallowed to crystallize in a column containing an inert support(stainless steel shot) by slowly reducing the temperature to 20° C. at acooling rate of 0.1° C./min. The column is equipped with an infrareddetector. An ATREF chromatogram curve is then generated by eluting thecrystallized polymer sample from the column by slowly increasing thetemperature of the eluting solvent (trichlorobenzene) from 20 to 120° C.at a rate of 1.5° C./min.

Specific Embodiments

The following specific embodiments of the invention and combinationsthereof are especially desirable and hereby delineated in order toprovide detailed disclosure for the appended claims.

1. A process for the polymerization of one or more additionpolymerizable monomers to form a polymer composition, said processcomprising contacting an addition polymerizable monomer or mixture ofmonomers in a reactor or reactor zone with a composition comprising atleast one polymerization catalyst and a cocatalyst under polymerizationconditions, terminating the polymerization, and recovering theterminated polymer, characterized in that at least a portion of saidpolymerization is conducted in the presence of a multi-centeredshuttling agent, thereby causing the composition to have a broadenedmolecular weight distribution.

2. An olefin polymer composition, especially such a copolymer comprisingin polymerized form ethylene and a copolymerizable comonomer, propyleneand at least one copolymerizable comonomer having from 4 to 20 carbons,or 4-methyl-1-pentene and at least one different copolymerizablecomonomer having from 4 to 20 carbons, said polymer composition having abimodal molecular weight distribution with the mean molecular weight ofthe higher molecular weight component exceeding the mean molecularweight of the lower molecular weight component by approximately aninteger multiple.

3. A polymer mixture comprising: (1) an organic or inorganic polymer,preferably a homopolymer of ethylene, a copolymer of ethylene and acopolymerizable comonomer, or a homopolymer of propylene; and (2) apolymer composition according to the present invention or preparedaccording to the process of the present invention.

4. A process according to embodiment 1 wherein the catalyst comprises ametal complex corresponding to the formula:

wherein:

R¹¹ is selected from alkyl, cycloalkyl, heteroalkyl, cycloheteroalkyl,aryl, and inertly substituted derivatives thereof containing from 1 to30 atoms not counting hydrogen or a divalent derivative thereof;

T¹ is a divalent bridging group of from 1 to 41 atoms other thanhydrogen, preferably 1 to 20 atoms other than hydrogen, and mostpreferably a mono- or di-C₁₋₂₀ hydrocarbyl substituted methylene orsilane group; and

R¹² is a C₅₋₂₀ heteroaryl group containing Lewis base functionality,especially a pyridin-2-yl- or substituted pyridin-2-yl group or adivalent derivative thereof;

M¹ is a Group 4 metal, preferably hafnium;

X¹ is an anionic, neutral or dianionic ligand group;

x′ is a number from 0 to 5 indicating the number of such X¹ groups; and

bonds, optional bonds and electron donative interactions are representedby lines, dotted lines and arrows respectively, or

a metal complex corresponding to the formula:

wherein

-   -   M² is a metal of Groups 4-10 of the Periodic Table of the        elements;    -   T² is a nitrogen, oxygen or phosphorus containing group;    -   X² is halo, hydrocarbyl, or hydrocarbyloxy;    -   t is one or two;    -   x″ is a number selected to provide charge balance;    -   and T² and N are linked by a bridging ligand.

5. A process according to any one of embodiments 1 or 4, characterizedby producing a polymer composition according to embodiment 2 or byproducing a polymer mixture according to embodiment 3.

6. A process for preparing an α,ω-difunctionalized polymer comprising:

a) contacting an addition polymerizable monomer or mixture of monomersin a reactor or reactor zone with a composition comprising at least onepolymerization catalyst and a cocatalyst under polymerization conditionsin the presence of a di-centered shuttling agent capable of transferringmetal center containing moieties to both termini of the growing polymerchain,

b) recovering a polymer terminally substituted at both termini with ametal center containing moiety; and

c) exchanging the terminal metal center moieties for the desiredfunctionality.

7. The process of embodiment 6 wherein the monomer or monomer mixturecomprises one or more C₂₋₂₀ α-olefins.

8. The process of embodiment 6 wherein ethylene is homopolymerized toprepare a polymer having a Mw from 500 to 10,000.

9. The process of any one of embodiments 6-8 wherein the exchange is anoxidation or displacement reaction and the resulting product is thecorresponding dihydroxyl- or divinyl-functionalized polymer.

The skilled artisan will appreciate that the invention disclosed hereinmay be practiced in the absence of any component which has not beenspecifically disclosed.

EXAMPLES

The following examples are provided as further illustration of theinvention and are not to be construed as limiting. The term “overnight”,if used, refers to a time of approximately 16-18 hours, the term “roomtemperature”, refers to a temperature of 20-25° C., and the term “mixedalkanes” refers to a commercially obtained mixture of C₆₋₉ aliphatichydrocarbons available under the trade designation Isopar E®, from ExxonMobil Chemicals Inc. In the event the name of a compound herein does notconform to the structural representation thereof, the structuralrepresentation shall control. The synthesis of all metal complexes andthe preparation of all screening experiments were carried out in a drynitrogen atmosphere using dry box techniques. All solvents used wereHPLC grade and were dried before their use.

MMAO refers to modified methylalumoxane, a triisobutylaluminum modifiedmethylalumoxane available commercially from Akzo-Noble Corporation.

Catalyst (A1) is[N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafniumdimethyl, prepared according to the teachings of WO 03/40195,2003US0204017, U.S. Ser. No. 10/429,024, filed May 2, 2003, and WO04/24740.

Catalyst (A2) is[N-(2,6-di(1-methylethyl)phenyl)amido)(2-methylphenyl)(1,2-phenylene-(6-pyridin-2-diyl)methane)]hafniumdimethyl, prepared according to the teachings of WO 03/40195,2003US0204017, U.S. Ser. No. 10/429,024, filed May 2, 2003, and WO04/24740.

Catalyst (A3) isbis[N,N′″-(2,4,6-tri(methylphenyl)amido)ethylenediamine]hafniumdibenzyl.

Catalyst (A4) isbis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxymethyl)cyclohexane-1,2-diylzirconium (IV) dibenzyl, prepared substantially according to theteachings of US-A-2004/0010103.

Catalyst (A5) is(bis-(1-methylethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)immino)zirconiumdibenzyl.

The preparation of catalyst (A5) is conducted as follows.

a) Preparation of (1-methylethyl)(2-hydroxy-3,5-di(t-butyl)phenyl)imine

3,5-Di-t-butylsalicylaldehyde (3.00 g) is added to 10 mL ofisopropylamine. The solution rapidly turns bright yellow. After stirringat ambient temperature for 3 hours, volatiles are removed under vacuumto yield a bright yellow, crystalline solid (97 percent yield).

b) Preparation of (bis-(1-methylethyl)(2-oxoyl-3,5-di(t-butylphenol)immino)zirconium dibenzyl

A solution of (1-methylethyl)(2-hydroxy-3,5-di(t-butyl)phenyl)imine (605mg, 2.2 mmol) in 5 mL toluene is slowly added to a solution ofZr(CH₂Ph)₄ (500 mg, 1.1 mmol) in 50 mL toluene. The resulting darkyellow solution is stirred for 30 min. Solvent is removed under reducedpressure to yield the desired product as a reddish-brown solid.

Catalyst (A6) isbis-(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)immino)zirconiumdibenzyl

The preparation of catalyst (A6) is conducted as follows.

a) Preparation of(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)imine

2-Methylcyclohexylamine (8.44 mL, 64.0 mmol) is dissolved in methanol(90 mL), and di-t-butylsalicaldehyde (10.00 g, 42.67 mmol) is added. Thereaction mixture is stirred for three hours and then cooled to −25° C.for 12 hrs. The resulting yellow solid precipitate is collected byfiltration and washed with cold methanol (2×15 mL), and then dried underreduced pressure. The yield is 11.17 g of a yellow solid. ¹H NMR isconsistent with the desired product as a mixture of isomers.

b) Preparation ofbis-(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)immino)zirconiumdibenzyl

A solution of(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)imine (7.63g, 23.2 mmol) in 200 mL toluene is slowly added to a solution ofZr(CH₂Ph)₄ (5.28 g, 11.6 mmol) in 600 mL toluene. The resulting darkyellow solution is stirred for 1 hour at 25° C. The solution is dilutedfurther with 680 mL toluene to give a solution having a concentration of0.00783 M.

Catalyst (A7) is(t-butylamido)dimethyl(3-N-pyrrolyl-1,2,3,3a,7a-η-inden-1-yl)silanetitaniumdimethyl prepared substantially according to the techniques of U.S. Pat.No. 6,268,444:

Catalyst (A8) is(t-butylamido)di(4-methylphenyl)(2-methyl-1,2,3,3a,7a-η-inden-1-yl)silanetitaniumdimethyl prepared substantially according to the teachings ofUS-A-2003/004286:

Catalyst (A9) is(t-butylamido)di(4-methylphenyl)(2-methyl-1,2,3,3a,8a-η-s-indacen-1-yl)silanetitaniumdimethyl prepared substantially according to the teachings ofUS-A-2003/004286:

Catalyst (A10) is bis(dimethyldisiloxane)(indene-1-yl)zirconiumdichloride available from Sigma-Aldrich:

Cocatalyst 1 A mixture of methyldi(C₁₄₋₁₈ alkyl)ammonium salts oftetrakis(pentafluorophenyl)borate (here-in-after armeenium borate),prepared by reaction of a long chain trialkylamine (Armeen™ M2HT,available from Akzo-Nobel, Inc.), HCl and Li[B(C₆F₅)₄], substantially asdisclosed in U.S. Pat. No. 5,919,9883, Ex. 2. Cocatalyst 2 Mixed C₁₄₋₁₈alkyldimethylammonium salt ofbis(tris(pentafluorophenyl)alumane)-2-undecylimidazolide, preparedaccording to U.S. Pat. No. 6,395,671, Ex. 16.

Multi-centered Shuttling Agents The multi-centered shuttling agentsemployed include (1,2-ethylene)di(zinc chloride) (MSA1),(1,2-ethylene)di(zinc bromide) (MSA2), (1,2-ethylene)di(ethylzinc)(MSA3), (1,2-ethylene)bis((trimethyl)silylzinc) (MSA4),(1,4-butylene)di(zinc-chloride) (MSA5), (1,4-butylene)di(zincbromide)(MSA6), (1,4-butylene)di(ethylzinc) (MSA7),(1,4-butylene)bis((trimethyl)silylzinc) (MSA8), bis(1,2-ethylenedizinc)(MSA9), bis(1,3-propylenedizinc) (MSA10), bis(1,4-butylenedizinc)(SA11), methyltri(1,2-ethylenezincchloride) (SA12) and(1,2-ethylene)bis(diethylaluminum) (SA13).

General High Throughput Parallel Polymerization Conditions

Polymerizations are conducted using a high throughput, parallelpolymerization reactor (PPR) available from Symyx technologies, Inc. andoperated substantially according to U.S. Pat. Nos. 6,248,540, 6,030,917,6,362,309, 6,306,658, and 6,316,663. Ethylene copolymerizations areconducted at 130° C. and 80 psi (550 kPa) with ethylene on demand using1.2 equivalents of cocatalyst 2 based on total catalyst used. A seriesof polymerizations are conducted in a parallel pressure reactor (PPR)comprised of 48 individual reactor cells in a 6×8 array that are fittedwith a pre-weighed glass tube. The working volume in each reactor cellis 6000 μL. Each cell is temperature and pressure controlled withstirring provided by individual stirring paddles. The monomer gas andquench gas (air) are plumbed directly into the PPR unit and controlledby automatic valves. Liquid reagents are robotically added to eachreactor cell by syringes and the reservoir solvent is mixed alkanes. Theorder of addition is mixed alkanes solvent (4 ml), ethylene, 1-octenecomonomer (143 mg), 0.419 μmol cocatalyst, multi-centered shuttlingagent in the indicated amounts, and finally, 0.3495 μmol catalyst A3.After quenching, the reactors are cooled and the glass tubes areunloaded. The tubes are transferred to a centrifuge/vacuum drying unit,and dried for 12 hours at 60° C. The tubes containing dried polymer areweighed and the difference between this weight and the tare weight givesthe net yield of polymer. The resulting polymer compositions aremeasured for molecular weight (Mw and Mn) using GPC-LALLS.Polydispersity Index (PDI=Mw/Mn) is calculated for each polymer. Thepresence of a broader polydispersity (Mw/Mn) and distinct bimodaldistribution indicates an effective multi-centered shuttling agentaccording to the invention.

1. A process for the polymerization of one or more additionpolymerizable monomers to form a polymer composition, said processcomprising: contacting an addition polymerizable monomer or mixture ofmonomers in a reactor or reactor zone with a composition comprising atleast one polymerization catalyst and a cocatalyst under polymerizationconditions and in the presence of a multi-centered shuttling agentcomprising at least a first chain shuttling moiety and a second chainshuttling moiety and having the following formula:(M′)_(m)A wherein M′ is a chain shuttling moiety, A is a linking group,the linking group being an organic group, and m is an integer from 2 to6; and forming a polymer composition comprising a first polymer free ofthe second chain shuttling moiety and a second polymer comprising thesecond chain shuttling moiety.
 2. The process according to claim 1wherein the catalyst comprises a metal complex corresponding to theformula:

wherein: R¹¹ is selected from alkyl, cycloalkyl, heteroalkyl,cycloheteroalkyl, aryl, and inertly substituted derivatives thereofcontaining from 1 to 30 atoms not counting hydrogen or a divalentderivative thereof; T¹ is a divalent bridging group of from 1 to 41atoms other than hydrogen, preferably 1 to 20 atoms other than hydrogen,and most preferably a mono- or di-C₁₋₂₀ hydrocarbyl substitutedmethylene or silane group; and R¹² is a C₅₋₂₀ heteroaryl groupcontaining Lewis base functionality, especially a pyridin-2-yl- orsubstituted pyridin-2-yl group or a divalent derivative thereof; M¹ is aGroup 4 metal, preferably hafnium; X¹ is an anionic, neutral ordianionic ligand group; x′ is a number from 0 to 5 indicating the numberof such X¹ groups; and bonds, optional bonds and electron donativeinteractions are represented by lines, dotted lines and arrowsrespectively, or a metal complex corresponding to the formula:

wherein M² is a metal of Groups 4-10 of the Periodic Table of theelements; T² is a nitrogen, oxygen or phosphorus containing group; X² ishalo, hydrocarbyl, or hydrocarbyloxy; t is one or two; x″ is a numberselected to provide charge balance; and T² and N are linked by abridging ligand.
 3. The process of claim 1 comprising forming asubstantially homogeneously polymer composition having a bimodalmolecular weight distribution.
 4. The process of claim 1 comprisingforming a second polymer with a molecular weight at least about twotimes the molecular weight of the first polymer.
 5. The process of claim1 comprising dividing the multi-centered chain shuttling agent into thefirst chain shuttling moiety and the second chain shuttling moiety. 6.The process of claim 5 comprising regenerating, after the attaching, amulti-centered chain shuttling agent comprising a polymer segmentattached thereto.